CVE-2025-40907

MEDIUM 5.3CVE-2025-40907 · Published 16/05/2025 · updated 17/06/2026

In short

CVE-2025-40907 is a MEDIUM (CVSS 5.3) vulnerability affecting fcgi (fastcgi).
Chance of exploitation in the next 30 days (EPSS): 0.68%, higher than 52.4% of all vulnerabilities.
No patched version is listed yet: follow the vendor's advisory in References.

Package	Affected versions	Patched versions
fcgi fastcgi	`≥ 0.44, ≤ 0.82`	No fix yet

Description

FCGI versions 0.44 through 0.82, for Perl, include a vulnerable version of the FastCGI fcgi2 (aka fcgi) library. The included FastCGI library is affected by CVE-2025-23016, causing 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.

References

openwall.com/lists/oss-security/2025/04/23/4 · Mailing List
FastCGI-Archives/fcgi2 · Exploit
FastCGI-Archives/fcgi2 release 2.4.5 · Release Notes
perl-catalyst/FCGI · Exploit
patch-diff.githubusercontent.com/raw/FastCGI-Archives/fcgi2/pull/74.patch · Patch
synacktiv.com/en/publications/cve-2025-23016-exploiting-the-fastcgi-library · Exploit

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