Integer overflow in Cesanta Mongoose
CVE-2025-51495
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.
Vulnerability class: Integer Overflow
EPSS: 0.004 (32.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Cesanta Mongoose
- N/a — versions n/a
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cve@mitre.org (Product)
- cve@mitre.org (Patch, Issue Tracking)
- cve@mitre.org (Exploit)
Frequently asked questions
- What is CVE-2025-51495?
- CVE-2025-51495 is a high-severity vulnerability in Cesanta Mongoose, classified under Integer Overflow or Wraparound. CVSS score: 7.5/10. Published 2025-09-29.
- How severe is CVE-2025-51495?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2025-51495 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.