CVE-2025-23016

CRITICAL 9.3

CVSS Score

9.3

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-190
Vendor	fastcgi
Product	fcgi
Published	Jan 10, 2025
Last Updated	Feb 26, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Scope

Confidentiality

Integrity

Availability

Affected Versions

FastCGI / fcgi

2.0.0 ≤ 2.4.4

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/FastCGI-Archives/fcgi2/issues/67 github.com: https://github.com/FastCGI-Archives/fcgi2/releases/tag/2.4.5 synacktiv.com: https://www.synacktiv.com/en/publications/cve-2025-23016-exploiting-the-fastcgi-library openwall.com: http://www.openwall.com/lists/oss-security/2025/04/23/4 lists.debian.org: https://lists.debian.org/debian-lts-announce/2025/10/msg00009.html