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315 vulnerabilities by Cesanta
CVE-2026-73261 (GCVE-0-2026-73261)
Vulnerability from nvd – Published: 2026-10-14 18:25 – Updated: 2026-10-14 18:25
VLAI
EPSS
VEX
Title
Mongoose: handle_opt() missing opts[1] > len check — 1-byte OOB read corrupts TCP MSS, silences mg_send() per connection
Summary
Mongoose is an embedded web server and network library. Prior to 7.23, the built-in TCP/IP stack enabled by MG_ENABLE_TCPIP in src/net_builtin.c does not reject a TCP option whose declared opts[1] length exceeds the remaining option bytes. In handle_opt(), a NOP followed by a truncated MSS option causes opts[3] to be read outside the declared options area and used as the low byte of dmss. An unauthenticated remote peer can corrupt the per-connection MSS value so later mg_send() calls transmit truncated or zero-length application payloads while the TCP connection otherwise appears healthy. This issue is fixed in version 7.23.
Severity
7.5 (High)
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/commit/cc7c6d… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.23 | x_refsource_MISC |
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CVE-2026-73260 (GCVE-0-2026-73260)
Vulnerability from nvd – Published: 2026-10-14 18:25 – Updated: 2026-10-14 18:25
VLAI
EPSS
VEX
Title
Mongoose: Out-of-bounds Read via length-counter underflow in built-in TLS X.509 DER parser
Summary
Mongoose is an embedded web server and network library. Prior to 7.23, the built-in TLS certificate parser selected by MG_TLS_BUILTIN fails to verify that a long-form DER element length fits within the remaining certificate buffer. In mg_der_to_tlv() and mg_der_next(), a peer-controlled length can advance the parser beyond the certificate and underflow the remaining uint32_t length, causing mg_tls_parse_cert_der() to continue walking an invalid pointer. An unauthenticated malicious TLS server, or a client presenting a certificate to a server configured for client certificates, can trigger an out-of-bounds read and denial of service during the handshake. This issue is fixed in version 7.23.
Severity
7.5 (High)
CWE
- CWE-125 - Out-of-bounds Read
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/commit/a8b4ae… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.23 | x_refsource_MISC |
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CVE-2026-73252 (GCVE-0-2026-73252)
Vulnerability from nvd – Published: 2026-10-14 18:24 – Updated: 2026-10-14 19:41
VLAI
EPSS
VEX
Title
Mongoose: Unauthenticated remote heap out-of-bounds read in built-in TLS: off-by-one length check in mg_tls_recv_record() underflows recv_len to SIZE_MAX
Summary
Mongoose is an embedded web server and network library. Prior to 7.23, the built-in TLS stack selected by MG_TLS_BUILTIN in src/tls_builtin.c accepts a TLS 1.3 record whose decrypted size is exactly the 16-byte authentication tag with no plaintext or ContentType byte. In mg_tls_recv_record(), the msgsz length check permits that record and the recv_len calculation underflows to SIZE_MAX, so a later handshake step treats stale buffer contents as a trusted message with an effectively unbounded length. An unauthenticated malicious TLS peer can trigger a heap out-of-bounds read before certificate or Finished validation, causing a remote denial of service. This issue is fixed in version 7.23.
Severity
7.5 (High)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-14 19:41 UTC
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/commit/758e30… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.23 | x_refsource_MISC |
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CVE-2026-63626 (GCVE-0-2026-63626)
Vulnerability from nvd – Published: 2026-10-14 18:26 – Updated: 2026-10-15 15:06
VLAI
EPSS
VEX
Title
Mongoose: ppp_handle_ipv6cp() uses attacker-controlled length without bounds check — OOB read and heap overflow (PPP/PPPoE, MG_ENABLE_IPV6)
Summary
Mongoose is an embedded web server and network library. Prior to 7.23, ppp_handle_ipv6cp() in src/l2_ppp.c trusts the 16-bit IPv6CP len field without checking it against the received payload size. On a PPP or PPPoE link using MG_ENABLE_TCPIP and MG_ENABLE_IPV6, an unauthenticated adjacent peer can complete the required LCP exchange and send a short Configure-Request with an oversized length, causing ppp_tx_frame() to read beyond recv_queue.buf and write beyond tx.buf. The same length misuse can also expose adjacent heap bytes in a reply or hang the event loop through find_opt(). This issue is fixed in version 7.23.
Severity
8.8 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-15 13:53 UTC
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/commit/751f14… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.23 | x_refsource_MISC |
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CVE-2026-101003 (GCVE-0-2026-101003)
Vulnerability from nvd – Published: 2026-09-28 05:30 – Updated: 2026-10-01 14:06 X_Open Source
VLAI
EPSS
VEX
Title
Cesanta Mongoose MQTT Broker main.c fn stack-based overflow
Summary
A weakness has been identified in Cesanta Mongoose up to 7.21. Affected by this vulnerability is the function fn of the file tutorials/mqtt/mqtt-server/main.c of the component MQTT Broker. Executing a manipulation can lead to stack-based buffer overflow. The attack can be launched remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 7.22 addresses this issue. This patch is called a9df523f76f43a38bd53b4232b9cfd4c16869e71. Upgrading the affected component is advised.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-01 14:06 UTC
Assigner
References
7 references
| URL | Tags |
|---|---|
| https://vuldb.com/vuln/410873 | vdb-entrytechnical-description |
| https://vuldb.com/vuln/410873/cti | signaturepermissions-required |
| https://vuldb.com/cve/CVE-2026-101003 | third-party-advisory |
| https://vuldb.com/submit/920005 | third-party-advisory |
| https://github.com/cesanta/mongoose/commit/a9df52… | patch |
| https://github.com/cesanta/mongoose/releases/tag/7.22 | patch |
| https://github.com/cesanta/mongoose/ | product |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Cesanta | Mongoose |
Affected:
7.0
Affected: 7.1 Affected: 7.2 Affected: 7.3 Affected: 7.4 Affected: 7.5 Affected: 7.6 Affected: 7.7 Affected: 7.8 Affected: 7.9 Affected: 7.10 Affected: 7.11 Affected: 7.12 Affected: 7.13 Affected: 7.14 Affected: 7.15 Affected: 7.16 Affected: 7.17 Affected: 7.18 Affected: 7.19 Affected: 7.20 Affected: 7.21 Unaffected: 7.22 cpe:2.3:a:cesanta:mongoose:*:*:*:*:*:*:*:* |
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CVE-2026-86716 (GCVE-0-2026-86716)
Vulnerability from nvd – Published: 2026-09-08 18:45 – Updated: 2026-09-08 19:08
VLAI
EPSS
VEX
Title
Cesanta mJS mjs_tok.c skip_spaces_and_comments heap-based overflow
Summary
A vulnerability was determined in Cesanta mJS up to 1.26. Affected is the function skip_spaces_and_comments of the file src/mjs_tok.c. Executing a manipulation can lead to heap-based buffer overflow. The attack can be launched remotely. The exploit has been publicly disclosed and may be utilized. The project was informed of the problem early through an issue report but has not responded yet.
Severity
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-08 19:07 UTC
Assigner
References
7 references
| URL | Tags |
|---|---|
| https://vuldb.com/vuln/399773 | vdb-entrytechnical-description |
| https://vuldb.com/vuln/399773/cti | signaturepermissions-required |
| https://vuldb.com/cve/CVE-2026-86716 | third-party-advisory |
| https://vuldb.com/submit/910881 | third-party-advisory |
| https://vuldb.com/submit/910882 | third-party-advisory |
| https://github.com/cesanta/mjs/issues/324 | exploitissue-tracking |
| https://github.com/cesanta/mjs/ | product |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Cesanta | mJS |
Affected:
1.0
Affected: 1.1 Affected: 1.2 Affected: 1.3 Affected: 1.4 Affected: 1.5 Affected: 1.6 Affected: 1.7 Affected: 1.8 Affected: 1.9 Affected: 1.10 Affected: 1.11 Affected: 1.12 Affected: 1.13 Affected: 1.14 Affected: 1.15 Affected: 1.16 Affected: 1.17 Affected: 1.18 Affected: 1.19 Affected: 1.20 Affected: 1.21 Affected: 1.22 Affected: 1.23 Affected: 1.24 Affected: 1.25 Affected: 1.26 cpe:2.3:a:cesanta:mjs:*:*:*:*:*:*:*:* |
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CVE-2026-73259 (GCVE-0-2026-73259)
Vulnerability from nvd – Published: 2026-08-20 17:39 – Updated: 2026-08-20 19:51
VLAI
EPSS
VEX
Title
Mongoose: Reflected XSS via decoded URI in directory listing render
Summary
Mongoose is an embedded web server and network library. Prior to 7.22, a remote attacker can send a crafted percent-encoded request path to a deployment using MG_ENABLE_DIRLIST and persuade a user to visit it. The mg_http_serve_dir() and listdir() path in src/http.c places the decoded request URI into the title and h1 elements without HTML entity encoding. The resulting reflected cross-site scripting executes in the Mongoose origin and can expose session data or perform actions as the victim. This issue is fixed in version 7.22.
Severity
5.4 (Medium)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-20 19:50 UTC
CWE
- CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/pull/3611 | x_refsource_MISC |
| https://github.com/cesanta/mongoose/commit/a9df52… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.22 | x_refsource_MISC |
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CVE-2026-73258 (GCVE-0-2026-73258)
Vulnerability from nvd – Published: 2026-08-20 17:36 – Updated: 2026-08-20 18:32
VLAI
EPSS
VEX
Title
Mongoose: Multipart boundary/header scan logic error in mg_http_next_multipart
Summary
Mongoose is an embedded web server and network library. Prior to 7.22, a remote attacker can place a lone carriage return or line feed in multipart input processed by mg_http_next_multipart() in src/http.c. The loops comparing s[b] and s[b + 1], and s[h2] and s[h2 + 1], use an incorrect AND condition and stop when either character resembles part of a CRLF terminator. This truncates headers, filenames, or boundaries and can cause an application to accept dangerous content after seeing a misleading Content-Type value. This issue is fixed in version 7.22.
Severity
6.5 (Medium)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-20 18:32 UTC
CWE
- CWE-697 - Incorrect Comparison
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/pull/3611 | x_refsource_MISC |
| https://github.com/cesanta/mongoose/commit/a9df52… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.22 | x_refsource_MISC |
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CVE-2026-73257 (GCVE-0-2026-73257)
Vulnerability from nvd – Published: 2026-08-20 17:30 – Updated: 2026-08-20 19:34
VLAI
EPSS
VEX
Title
Mongoose: Content-Length + Transfer-Encoding coexistence enables request smuggling
Summary
Mongoose is an embedded web server and network library. Priro to version 7.22, a remote unauthenticated attacker can send an HTTP request containing both Content-Length and Transfer-Encoding: chunked. The cl_count and te_count checks in the mg_http_parse() and http_cb() paths in src/http.c accept both headers and prioritize chunked encoding, while a Content-Length-preferring reverse proxy can use a different request boundary. This CL.TE desynchronization can inject requests that access or modify resources in another user context. This issue is fixed in version 7.22.
Severity
9.1 (Critical)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-20 19:34 UTC
CWE
- CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/pull/3611 | x_refsource_MISC |
| https://github.com/cesanta/mongoose/commit/a9df52… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.22 | x_refsource_MISC |
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CVE-2026-73256 (GCVE-0-2026-73256)
Vulnerability from nvd – Published: 2026-08-20 17:37 – Updated: 2026-08-21 21:46
VLAI
EPSS
VEX
Title
Mongoose: HTTP/1.0 detection off-by-one enables request smuggling via chunked TE
Summary
Mongoose is an embedded web server and network library. Prior to 7.22, a remote unauthenticated attacker can exploit an HTTP/1.0 reverse-proxy deployment by sending a request with Transfer-Encoding: chunked and conflicting framing. The http_cb() function in src/http.c tests hm.proto.len with an impossible greater-than-eight condition even though mg_http_parse() requires an eight-byte protocol string, so is_http_1_0 is never set. Mongoose consequently processes chunked encoding that an HTTP/1.0 proxy can ignore, enabling request smuggling and unauthorized access or state changes. This issue is fixed in version 7.22.
Severity
9.1 (Critical)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-21 21:10 UTC
CWE
- CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/pull/3611 | x_refsource_MISC |
| https://github.com/cesanta/mongoose/commit/a9df52… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.22 | x_refsource_MISC |
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CVE-2026-73255 (GCVE-0-2026-73255)
Vulnerability from nvd – Published: 2026-08-20 17:40 – Updated: 2026-08-25 15:09
VLAI
EPSS
VEX
Title
Mongoose: Path traversal in SSI #include directives enables arbitrary file read
Summary
Mongoose is an embedded web server and network library. Prior to 7.22, an attacker who can control an SSI-enabled file can place directory traversal sequences in an #include file or #include virtual directive. The mg_ssi() function in src/ssi.c concatenates the directive argument into a filesystem path without calling mg_path_is_sane(), allowing an MG_ENABLE_SSI deployment with ssi_pattern configured to disclose files readable by the Mongoose process. This issue is fixed in version 7.22.
Severity
6.5 (Medium)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-25 15:09 UTC
CWE
- CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/pull/3611 | x_refsource_MISC |
| https://github.com/cesanta/mongoose/commit/a9df52… | x_refsource_MISC |
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CVE-2026-73254 (GCVE-0-2026-73254)
Vulnerability from nvd – Published: 2026-08-20 17:37 – Updated: 2026-08-21 16:22
VLAI
EPSS
VEX
Title
Mongoose: Stored XSS via unescaped filenames in directory listing
Summary
Mongoose is an embedded web server and network library. Prior to 7.22, an attacker who can create a file with an HTML payload in its name can trigger stored cross-site scripting when a user browses a directory served with MG_ENABLE_DIRLIST. The printdirentry() path called by listdir() in src/http.c URL-encodes the href but inserts the raw filesystem filename into the HTML link text. The browser executes the injected markup in the Mongoose origin, which can expose session data or permit actions as the victim. This issue is fixed in version 7.22.
Severity
5.4 (Medium)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-21 16:21 UTC
CWE
- CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/pull/3611 | x_refsource_MISC |
| https://github.com/cesanta/mongoose/commit/a9df52… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.22 | x_refsource_MISC |
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CVE-2026-73253 (GCVE-0-2026-73253)
Vulnerability from nvd – Published: 2026-08-20 17:41 – Updated: 2026-08-20 18:36
VLAI
EPSS
VEX
Title
Mongoose: TLS Hostname Verification Bypass via Overly Permissive Wildcard Matching
Summary
Mongoose is an embedded web server and network library. Prior to version 7.22, an on-path network attacker with a wildcard certificate for a parent domain can impersonate deeper subdomains to a client using the built-in TLS stack. The mg_tls_verify_cert_san() and mg_tls_verify_cert_cn() functions in src/tls_builtin.c call mg_match(), whose wildcard can cross DNS label boundaries, so a pattern such as *.example.com can match foo.bar.example.com. The resulting hostname verification bypass permits interception and modification of TLS traffic. This issue is fixed in version 7.22.
Severity
SSVC
Exploitation: poc
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-20 18:33 UTC
CWE
- CWE-295 - Improper Certificate Validation
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/pull/3611 | x_refsource_MISC |
| https://github.com/cesanta/mongoose/commit/a9df52… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.22 | x_refsource_MISC |
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CVE-2026-73251 (GCVE-0-2026-73251)
Vulnerability from nvd – Published: 2026-08-20 17:34 – Updated: 2026-08-20 19:50
VLAI
EPSS
VEX
Title
Mongoose Built-in TLS: CA-bundle certificate chain accepted without any signature verification
Summary
Mongoose is an embedded web server and network library. Prior to 7.23, a network attacker can impersonate a TLS server to a Mongoose client configured with a multi-certificate CA bundle. In src/tls_builtin.c, the mg_tls_init() function stores the bundle in tls->ca_bundle_der while tls->ca_der.len remains zero, and mg_tls_recv_cert() uses tls_bundle_find() to accept a Common Name match without calling mg_tls_verify_cert_signature(). A forged self-signed certificate can therefore satisfy hostname and CertificateVerify checks and enable interception, credential disclosure, traffic modification, and malicious responses. This issue is fixed in version 7.23.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-20 19:50 UTC
CWE
- CWE-295 - Improper Certificate Validation
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/commit/2988bc… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.23 | x_refsource_MISC |
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CVE-2026-11404 (GCVE-0-2026-11404)
Vulnerability from nvd – Published: 2026-07-09 15:13 – Updated: 2026-08-29 13:38
VLAI
EPSS
VEX
Title
Cesanta Mongoose Out-of-Bounds Read in MG_TLS_BUILTIN ClientHello Session ID Parsing
Summary
Cesanta Mongoose before 7.22 contains an out-of-bounds read in the built-in TLS server function mg_tls_server_recv_hello(), which uses an attacker-controlled session_id_len byte from a TLS ClientHello as a buffer index without validating it against the length of received data. A remote, unauthenticated attacker can send a single crafted ClientHello with an oversized session id length to read past the receive buffer, crashing any HTTPS, MQTTS, or WSS service built on MG_TLS_BUILTIN.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-09 16:09 UTC
CWE
- CWE-125 - Out-of-bounds Read
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/releases/tag/7.22 | patchrelease-notes |
| https://github.com/cesanta/mongoose | product |
Impacted products
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CVE-2026-63626 (GCVE-0-2026-63626)
Vulnerability from cvelistv5 – Published: 2026-10-14 18:26 – Updated: 2026-10-15 15:06
VLAI
EPSS
VEX
Title
Mongoose: ppp_handle_ipv6cp() uses attacker-controlled length without bounds check — OOB read and heap overflow (PPP/PPPoE, MG_ENABLE_IPV6)
Summary
Mongoose is an embedded web server and network library. Prior to 7.23, ppp_handle_ipv6cp() in src/l2_ppp.c trusts the 16-bit IPv6CP len field without checking it against the received payload size. On a PPP or PPPoE link using MG_ENABLE_TCPIP and MG_ENABLE_IPV6, an unauthenticated adjacent peer can complete the required LCP exchange and send a short Configure-Request with an oversized length, causing ppp_tx_frame() to read beyond recv_queue.buf and write beyond tx.buf. The same length misuse can also expose adjacent heap bytes in a reply or hang the event loop through find_opt(). This issue is fixed in version 7.23.
Severity
8.8 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-15 13:53 UTC
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/commit/751f14… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.23 | x_refsource_MISC |
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CVE-2026-73261 (GCVE-0-2026-73261)
Vulnerability from cvelistv5 – Published: 2026-10-14 18:25 – Updated: 2026-10-14 18:25
VLAI
EPSS
VEX
Title
Mongoose: handle_opt() missing opts[1] > len check — 1-byte OOB read corrupts TCP MSS, silences mg_send() per connection
Summary
Mongoose is an embedded web server and network library. Prior to 7.23, the built-in TCP/IP stack enabled by MG_ENABLE_TCPIP in src/net_builtin.c does not reject a TCP option whose declared opts[1] length exceeds the remaining option bytes. In handle_opt(), a NOP followed by a truncated MSS option causes opts[3] to be read outside the declared options area and used as the low byte of dmss. An unauthenticated remote peer can corrupt the per-connection MSS value so later mg_send() calls transmit truncated or zero-length application payloads while the TCP connection otherwise appears healthy. This issue is fixed in version 7.23.
Severity
7.5 (High)
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/commit/cc7c6d… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.23 | x_refsource_MISC |
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CVE-2026-73260 (GCVE-0-2026-73260)
Vulnerability from cvelistv5 – Published: 2026-10-14 18:25 – Updated: 2026-10-14 18:25
VLAI
EPSS
VEX
Title
Mongoose: Out-of-bounds Read via length-counter underflow in built-in TLS X.509 DER parser
Summary
Mongoose is an embedded web server and network library. Prior to 7.23, the built-in TLS certificate parser selected by MG_TLS_BUILTIN fails to verify that a long-form DER element length fits within the remaining certificate buffer. In mg_der_to_tlv() and mg_der_next(), a peer-controlled length can advance the parser beyond the certificate and underflow the remaining uint32_t length, causing mg_tls_parse_cert_der() to continue walking an invalid pointer. An unauthenticated malicious TLS server, or a client presenting a certificate to a server configured for client certificates, can trigger an out-of-bounds read and denial of service during the handshake. This issue is fixed in version 7.23.
Severity
7.5 (High)
CWE
- CWE-125 - Out-of-bounds Read
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/commit/a8b4ae… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.23 | x_refsource_MISC |
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CVE-2026-73252 (GCVE-0-2026-73252)
Vulnerability from cvelistv5 – Published: 2026-10-14 18:24 – Updated: 2026-10-14 19:41
VLAI
EPSS
VEX
Title
Mongoose: Unauthenticated remote heap out-of-bounds read in built-in TLS: off-by-one length check in mg_tls_recv_record() underflows recv_len to SIZE_MAX
Summary
Mongoose is an embedded web server and network library. Prior to 7.23, the built-in TLS stack selected by MG_TLS_BUILTIN in src/tls_builtin.c accepts a TLS 1.3 record whose decrypted size is exactly the 16-byte authentication tag with no plaintext or ContentType byte. In mg_tls_recv_record(), the msgsz length check permits that record and the recv_len calculation underflows to SIZE_MAX, so a later handshake step treats stale buffer contents as a trusted message with an effectively unbounded length. An unauthenticated malicious TLS peer can trigger a heap out-of-bounds read before certificate or Finished validation, causing a remote denial of service. This issue is fixed in version 7.23.
Severity
7.5 (High)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-14 19:41 UTC
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/commit/758e30… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.23 | x_refsource_MISC |
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CVE-2026-101003 (GCVE-0-2026-101003)
Vulnerability from cvelistv5 – Published: 2026-09-28 05:30 – Updated: 2026-10-01 14:06 X_Open Source
VLAI
EPSS
VEX
Title
Cesanta Mongoose MQTT Broker main.c fn stack-based overflow
Summary
A weakness has been identified in Cesanta Mongoose up to 7.21. Affected by this vulnerability is the function fn of the file tutorials/mqtt/mqtt-server/main.c of the component MQTT Broker. Executing a manipulation can lead to stack-based buffer overflow. The attack can be launched remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 7.22 addresses this issue. This patch is called a9df523f76f43a38bd53b4232b9cfd4c16869e71. Upgrading the affected component is advised.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-01 14:06 UTC
Assigner
References
7 references
| URL | Tags |
|---|---|
| https://vuldb.com/vuln/410873 | vdb-entrytechnical-description |
| https://vuldb.com/vuln/410873/cti | signaturepermissions-required |
| https://vuldb.com/cve/CVE-2026-101003 | third-party-advisory |
| https://vuldb.com/submit/920005 | third-party-advisory |
| https://github.com/cesanta/mongoose/commit/a9df52… | patch |
| https://github.com/cesanta/mongoose/releases/tag/7.22 | patch |
| https://github.com/cesanta/mongoose/ | product |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Cesanta | Mongoose |
Affected:
7.0
Affected: 7.1 Affected: 7.2 Affected: 7.3 Affected: 7.4 Affected: 7.5 Affected: 7.6 Affected: 7.7 Affected: 7.8 Affected: 7.9 Affected: 7.10 Affected: 7.11 Affected: 7.12 Affected: 7.13 Affected: 7.14 Affected: 7.15 Affected: 7.16 Affected: 7.17 Affected: 7.18 Affected: 7.19 Affected: 7.20 Affected: 7.21 Unaffected: 7.22 cpe:2.3:a:cesanta:mongoose:*:*:*:*:*:*:*:* |
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CVE-2026-86716 (GCVE-0-2026-86716)
Vulnerability from cvelistv5 – Published: 2026-09-08 18:45 – Updated: 2026-09-08 19:08
VLAI
EPSS
VEX
Title
Cesanta mJS mjs_tok.c skip_spaces_and_comments heap-based overflow
Summary
A vulnerability was determined in Cesanta mJS up to 1.26. Affected is the function skip_spaces_and_comments of the file src/mjs_tok.c. Executing a manipulation can lead to heap-based buffer overflow. The attack can be launched remotely. The exploit has been publicly disclosed and may be utilized. The project was informed of the problem early through an issue report but has not responded yet.
Severity
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-08 19:07 UTC
Assigner
References
7 references
| URL | Tags |
|---|---|
| https://vuldb.com/vuln/399773 | vdb-entrytechnical-description |
| https://vuldb.com/vuln/399773/cti | signaturepermissions-required |
| https://vuldb.com/cve/CVE-2026-86716 | third-party-advisory |
| https://vuldb.com/submit/910881 | third-party-advisory |
| https://vuldb.com/submit/910882 | third-party-advisory |
| https://github.com/cesanta/mjs/issues/324 | exploitissue-tracking |
| https://github.com/cesanta/mjs/ | product |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Cesanta | mJS |
Affected:
1.0
Affected: 1.1 Affected: 1.2 Affected: 1.3 Affected: 1.4 Affected: 1.5 Affected: 1.6 Affected: 1.7 Affected: 1.8 Affected: 1.9 Affected: 1.10 Affected: 1.11 Affected: 1.12 Affected: 1.13 Affected: 1.14 Affected: 1.15 Affected: 1.16 Affected: 1.17 Affected: 1.18 Affected: 1.19 Affected: 1.20 Affected: 1.21 Affected: 1.22 Affected: 1.23 Affected: 1.24 Affected: 1.25 Affected: 1.26 cpe:2.3:a:cesanta:mjs:*:*:*:*:*:*:*:* |
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CVE-2026-73253 (GCVE-0-2026-73253)
Vulnerability from cvelistv5 – Published: 2026-08-20 17:41 – Updated: 2026-08-20 18:36
VLAI
EPSS
VEX
Title
Mongoose: TLS Hostname Verification Bypass via Overly Permissive Wildcard Matching
Summary
Mongoose is an embedded web server and network library. Prior to version 7.22, an on-path network attacker with a wildcard certificate for a parent domain can impersonate deeper subdomains to a client using the built-in TLS stack. The mg_tls_verify_cert_san() and mg_tls_verify_cert_cn() functions in src/tls_builtin.c call mg_match(), whose wildcard can cross DNS label boundaries, so a pattern such as *.example.com can match foo.bar.example.com. The resulting hostname verification bypass permits interception and modification of TLS traffic. This issue is fixed in version 7.22.
Severity
SSVC
Exploitation: poc
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-20 18:33 UTC
CWE
- CWE-295 - Improper Certificate Validation
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/pull/3611 | x_refsource_MISC |
| https://github.com/cesanta/mongoose/commit/a9df52… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.22 | x_refsource_MISC |
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CVE-2026-73255 (GCVE-0-2026-73255)
Vulnerability from cvelistv5 – Published: 2026-08-20 17:40 – Updated: 2026-08-25 15:09
VLAI
EPSS
VEX
Title
Mongoose: Path traversal in SSI #include directives enables arbitrary file read
Summary
Mongoose is an embedded web server and network library. Prior to 7.22, an attacker who can control an SSI-enabled file can place directory traversal sequences in an #include file or #include virtual directive. The mg_ssi() function in src/ssi.c concatenates the directive argument into a filesystem path without calling mg_path_is_sane(), allowing an MG_ENABLE_SSI deployment with ssi_pattern configured to disclose files readable by the Mongoose process. This issue is fixed in version 7.22.
Severity
6.5 (Medium)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-25 15:09 UTC
CWE
- CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/pull/3611 | x_refsource_MISC |
| https://github.com/cesanta/mongoose/commit/a9df52… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.22 | x_refsource_MISC |
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CVE-2026-73259 (GCVE-0-2026-73259)
Vulnerability from cvelistv5 – Published: 2026-08-20 17:39 – Updated: 2026-08-20 19:51
VLAI
EPSS
VEX
Title
Mongoose: Reflected XSS via decoded URI in directory listing render
Summary
Mongoose is an embedded web server and network library. Prior to 7.22, a remote attacker can send a crafted percent-encoded request path to a deployment using MG_ENABLE_DIRLIST and persuade a user to visit it. The mg_http_serve_dir() and listdir() path in src/http.c places the decoded request URI into the title and h1 elements without HTML entity encoding. The resulting reflected cross-site scripting executes in the Mongoose origin and can expose session data or perform actions as the victim. This issue is fixed in version 7.22.
Severity
5.4 (Medium)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-20 19:50 UTC
CWE
- CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/pull/3611 | x_refsource_MISC |
| https://github.com/cesanta/mongoose/commit/a9df52… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.22 | x_refsource_MISC |
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CVE-2026-73256 (GCVE-0-2026-73256)
Vulnerability from cvelistv5 – Published: 2026-08-20 17:37 – Updated: 2026-08-21 21:46
VLAI
EPSS
VEX
Title
Mongoose: HTTP/1.0 detection off-by-one enables request smuggling via chunked TE
Summary
Mongoose is an embedded web server and network library. Prior to 7.22, a remote unauthenticated attacker can exploit an HTTP/1.0 reverse-proxy deployment by sending a request with Transfer-Encoding: chunked and conflicting framing. The http_cb() function in src/http.c tests hm.proto.len with an impossible greater-than-eight condition even though mg_http_parse() requires an eight-byte protocol string, so is_http_1_0 is never set. Mongoose consequently processes chunked encoding that an HTTP/1.0 proxy can ignore, enabling request smuggling and unauthorized access or state changes. This issue is fixed in version 7.22.
Severity
9.1 (Critical)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-21 21:10 UTC
CWE
- CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/pull/3611 | x_refsource_MISC |
| https://github.com/cesanta/mongoose/commit/a9df52… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.22 | x_refsource_MISC |
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CVE-2026-73254 (GCVE-0-2026-73254)
Vulnerability from cvelistv5 – Published: 2026-08-20 17:37 – Updated: 2026-08-21 16:22
VLAI
EPSS
VEX
Title
Mongoose: Stored XSS via unescaped filenames in directory listing
Summary
Mongoose is an embedded web server and network library. Prior to 7.22, an attacker who can create a file with an HTML payload in its name can trigger stored cross-site scripting when a user browses a directory served with MG_ENABLE_DIRLIST. The printdirentry() path called by listdir() in src/http.c URL-encodes the href but inserts the raw filesystem filename into the HTML link text. The browser executes the injected markup in the Mongoose origin, which can expose session data or permit actions as the victim. This issue is fixed in version 7.22.
Severity
5.4 (Medium)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-21 16:21 UTC
CWE
- CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/pull/3611 | x_refsource_MISC |
| https://github.com/cesanta/mongoose/commit/a9df52… | x_refsource_MISC |
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CVE-2026-73258 (GCVE-0-2026-73258)
Vulnerability from cvelistv5 – Published: 2026-08-20 17:36 – Updated: 2026-08-20 18:32
VLAI
EPSS
VEX
Title
Mongoose: Multipart boundary/header scan logic error in mg_http_next_multipart
Summary
Mongoose is an embedded web server and network library. Prior to 7.22, a remote attacker can place a lone carriage return or line feed in multipart input processed by mg_http_next_multipart() in src/http.c. The loops comparing s[b] and s[b + 1], and s[h2] and s[h2 + 1], use an incorrect AND condition and stop when either character resembles part of a CRLF terminator. This truncates headers, filenames, or boundaries and can cause an application to accept dangerous content after seeing a misleading Content-Type value. This issue is fixed in version 7.22.
Severity
6.5 (Medium)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-20 18:32 UTC
CWE
- CWE-697 - Incorrect Comparison
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/pull/3611 | x_refsource_MISC |
| https://github.com/cesanta/mongoose/commit/a9df52… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.22 | x_refsource_MISC |
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CVE-2026-73251 (GCVE-0-2026-73251)
Vulnerability from cvelistv5 – Published: 2026-08-20 17:34 – Updated: 2026-08-20 19:50
VLAI
EPSS
VEX
Title
Mongoose Built-in TLS: CA-bundle certificate chain accepted without any signature verification
Summary
Mongoose is an embedded web server and network library. Prior to 7.23, a network attacker can impersonate a TLS server to a Mongoose client configured with a multi-certificate CA bundle. In src/tls_builtin.c, the mg_tls_init() function stores the bundle in tls->ca_bundle_der while tls->ca_der.len remains zero, and mg_tls_recv_cert() uses tls_bundle_find() to accept a Common Name match without calling mg_tls_verify_cert_signature(). A forged self-signed certificate can therefore satisfy hostname and CertificateVerify checks and enable interception, credential disclosure, traffic modification, and malicious responses. This issue is fixed in version 7.23.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-20 19:50 UTC
CWE
- CWE-295 - Improper Certificate Validation
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/commit/2988bc… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.23 | x_refsource_MISC |
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CVE-2026-73257 (GCVE-0-2026-73257)
Vulnerability from cvelistv5 – Published: 2026-08-20 17:30 – Updated: 2026-08-20 19:34
VLAI
EPSS
VEX
Title
Mongoose: Content-Length + Transfer-Encoding coexistence enables request smuggling
Summary
Mongoose is an embedded web server and network library. Priro to version 7.22, a remote unauthenticated attacker can send an HTTP request containing both Content-Length and Transfer-Encoding: chunked. The cl_count and te_count checks in the mg_http_parse() and http_cb() paths in src/http.c accept both headers and prioritize chunked encoding, while a Content-Length-preferring reverse proxy can use a different request boundary. This CL.TE desynchronization can inject requests that access or modify resources in another user context. This issue is fixed in version 7.22.
Severity
9.1 (Critical)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-20 19:34 UTC
CWE
- CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/security/advi… | x_refsource_CONFIRM |
| https://github.com/cesanta/mongoose/pull/3611 | x_refsource_MISC |
| https://github.com/cesanta/mongoose/commit/a9df52… | x_refsource_MISC |
| https://github.com/cesanta/mongoose/releases/tag/7.22 | x_refsource_MISC |
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CVE-2026-11404 (GCVE-0-2026-11404)
Vulnerability from cvelistv5 – Published: 2026-07-09 15:13 – Updated: 2026-08-29 13:38
VLAI
EPSS
VEX
Title
Cesanta Mongoose Out-of-Bounds Read in MG_TLS_BUILTIN ClientHello Session ID Parsing
Summary
Cesanta Mongoose before 7.22 contains an out-of-bounds read in the built-in TLS server function mg_tls_server_recv_hello(), which uses an attacker-controlled session_id_len byte from a TLS ClientHello as a buffer index without validating it against the length of received data. A remote, unauthenticated attacker can send a single crafted ClientHello with an oversized session id length to read past the receive buffer, crashing any HTTPS, MQTTS, or WSS service built on MG_TLS_BUILTIN.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-09 16:09 UTC
CWE
- CWE-125 - Out-of-bounds Read
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://github.com/cesanta/mongoose/releases/tag/7.22 | patchrelease-notes |
| https://github.com/cesanta/mongoose | product |
Impacted products
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