CVE-2025-23016: FastCGI Fcgi

Critical severity, CVSS 9.3. EPSS: 0.6% chance of exploitation in the next 30 days.

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.

Affected products

• FastCGI Fcgi: from 2.0.0, up to and including 2.4.4

Published 2025-01-10. Last modified 2026-06-17.