An integer overflow vulnerability exists in the WebSocket component of Mongoose 7.5 thru…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-190 and the CVSS impact.
Summary
An integer overflow vulnerability exists in the WebSocket component of Mongoose 7.5 thru 7.17. By sending a specially crafted WebSocket request, an attacker can cause the application to crash. If downstream vendors integrate this component improperly, the issue may lead to a buffer overflow.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2025-51495
- 2026-10-03 Alias added: GHSA-83rc-g55p-8xj2
References
More Cesanta Mongoose vulnerabilities
- TI-2026-51393 Mongoose: Content-Length + Transfer-Encoding coexistence enables request smuggling CVSS 3.1CRITICAL 9.1
- TI-2026-51389 Mongoose: TLS Hostname Verification Bypass via Overly Permissive Wildcard Matching CVSS 4.0CRITICAL 9.1
- TI-2023-02723 Cesanta Mongoose MQTT Message Parsing Heap Overflow CVSS 3.1HIGH 8.8
- TI-2020-15865 Buffer overflow in mg_resolve_from_hosts_file in Mongoose 6.18, when reading from a crafted hosts file. CVSS 3.1HIGH 8.8
- TI-2023-17032 The HTTP server in Mongoose before 7.10 accepts requests containing negative… CVSS 3.1HIGH 7.5
- TI-2026-06113 Cesanta Mongoose TCP Option net_builtin.c handle_opt infinite loop CVSS 4.0MEDIUM 6.9
Sources
- CVE-2025-51495 · CVE Program
- CVE-2025-51495 · NVD
- FIRST EPSS
- GHSA-83rc-g55p-8xj2 · GitHub Advisory Database · CC BY 4.0
- CVE-2025-51495 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences