Vulnerability Description
FastCGI fcgi2 (aka fcgi) 2.x through 2.4.4 has an integer overflow (and resultant heap-based buffer overflow) via crafted nameLen or valueLen values in data to the IPC socket. This occurs in ReadParams in fcgiapp.c.
CVSS Score
CRITICAL
Related Weaknesses (CWE)
References
- https://github.com/FastCGI-Archives/fcgi2/issues/67
- https://github.com/FastCGI-Archives/fcgi2/releases/tag/2.4.5
- https://www.synacktiv.com/en/publications/cve-2025-23016-exploiting-the-fastcgi-
- http://www.openwall.com/lists/oss-security/2025/04/23/4
- https://lists.debian.org/debian-lts-announce/2025/10/msg00009.html
- https://www.synacktiv.com/en/publications/cve-2025-23016-exploiting-the-fastcgi-
FAQ
What is CVE-2025-23016?
CVE-2025-23016 is a vulnerability with a CVSS score of 9.3 (CRITICAL). FastCGI fcgi2 (aka fcgi) 2.x through 2.4.4 has an integer overflow (and resultant heap-based buffer overflow) via crafted nameLen or valueLen values in data to the IPC socket. This occurs in ReadParam...
How severe is CVE-2025-23016?
CVE-2025-23016 has been rated CRITICAL with a CVSS base score of 9.3/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2025-23016?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.