Vulnerability-Lookup

GHSA-9935-W26G-XF2M

Vulnerability from github – Published: 2026-10-10 12:30 – Updated: 2026-10-10 15:30

Details

Out-of-bounds read in the VarOpt union deserialization of Apache DataSketches C++ (repo: datasketches-cpp).

var_opt_union::deserialize() read the 32-byte preamble of a non-empty union after checking that only 8 bytes were available, so a truncated serialized union could cause a read of up to 24 bytes past the end of the input. For such inputs, the size remaining for the embedded sketch was also computed by an unsigned subtraction that could wrap around, so the embedded sketch's own size checks no longer limited reads to the input. The bytes read can become part of the deserialized union's state. This can cause a crash (denial of service) and could expose adjacent memory contents.

This issue affects Apache DataSketches C++: from 2.0.0-incubating before 5.3.0. Only applications that deserialize VarOpt unions from untrusted sources are affected.

Users are recommended to upgrade to version 5.3.0, which fixes this issue.

Show details on source website

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{
  "affected": [],
  "aliases": [
    "CVE-2026-103636"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-125"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-10T11:17:36Z",
    "severity": null
  },
  "details": "Out-of-bounds read in the VarOpt union deserialization of Apache DataSketches C++ (repo: datasketches-cpp).\n\nvar_opt_union::deserialize() read the 32-byte preamble of a non-empty union after checking that only 8 bytes were available, so a truncated serialized union could cause a read of up to 24 bytes past the end of the input. For such inputs, the size remaining for the embedded sketch was also computed by an unsigned subtraction that could wrap around, so the embedded sketch\u0027s own size checks no longer limited reads to the input. The bytes read can become part of the deserialized union\u0027s state. This can cause a crash (denial of service) and could expose adjacent memory contents.\n\nThis issue affects Apache DataSketches C++: from 2.0.0-incubating before 5.3.0. Only applications that deserialize VarOpt unions from untrusted sources are affected.\n\nUsers are recommended to upgrade to version 5.3.0, which fixes this issue.",
  "id": "GHSA-9935-w26g-xf2m",
  "modified": "2026-10-10T15:30:21Z",
  "published": "2026-10-10T12:30:25Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-103636"
    },
    {
      "type": "WEB",
      "url": "https://github.com/apache/datasketches-cpp/releases/tag/5.3.0"
    },
    {
      "type": "WEB",
      "url": "https://lists.apache.org/thread/znn94s463w7wy125khcywxsp82y2qkq5"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/10/10/6"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-103636 (GCVE-0-2026-103636)

Vulnerability from cvelistv5 – Published: 2026-10-10 10:23 – Updated: 2026-10-10 12:10

Title

Apache DataSketches: datasketches-cpp: Out-of-bounds read in VarOpt union deserialization allows denial of service via a truncated sketch

Summary

Out-of-bounds read in the VarOpt union deserialization of Apache DataSketches C++ (repo: datasketches-cpp). var_opt_union::deserialize() read the 32-byte preamble of a non-empty union after checking that only 8 bytes were available, so a truncated serialized union could cause a read of up to 24 bytes past the end of the input. For such inputs, the size remaining for the embedded sketch was also computed by an unsigned subtraction that could wrap around, so the embedded sketch's own size checks no longer limited reads to the input. The bytes read can become part of the deserialized union's state. This can cause a crash (denial of service) and could expose adjacent memory contents. This issue affects Apache DataSketches C++: from 2.0.0-incubating before 5.3.0. Only applications that deserialize VarOpt unions from untrusted sources are affected. Users are recommended to upgrade to version 5.3.0, which fixes this issue.

Severity

No CVSS data available.

CWE

CWE-125 - Out-of-bounds read
CWE-191 - Integer underflow (wrap or wraparound)

Assigner

apache CNA under the mitre root

CNA scorecard B 76/100 over 939 records in the last 180 days details

References

3 references

URL	Tags
https://lists.apache.org/thread/znn94s463w7wy125k…	vendor-advisory
https://github.com/apache/datasketches-cpp/releas…	release-notes
http://www.openwall.com/lists/oss-security/2026/10/10/6

Impacted products

1 product

Vendor	Product	Version
Apache Software Foundation	Apache DataSketches	Affected: 2.0.0-incubating , ≤ 5.2.0 (semver)

Credits

He Huang NexusSan

Show details on NVD website

JSON

To clipboard

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-9935-W26G-XF2M

CVE-2026-103636 (GCVE-0-2026-103636)

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