CVE-2025-23016
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
02 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
03 Exploitation and scoring
- Exploitation
- Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.
- SSVC decision
- ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
- EPSS probability
- 0.61% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 49.0% of scored records. A rank, not a probability.
- NVD base score
- 9.3 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- NVD analysis status
- Deferred. NVD last modified this record on 2026-06-17.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2025-01-10 00:00Z1 YR AGO
- Last updated
- 2026-02-26 19:09Z8 MO AGO
- Reserved
- 2025-01-10
- Assigning CNA
- mitre
- Record state
- PUBLISHED
- Severity
- Critical (CVSS 9.3)
- CNA CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- Weaknesses
- CWE-190Integer Overflow or WraparoundBase
- Data version
- 5.2
- Document digest
- 752c2d75afae7e7e971f1d7c15055ad186d4baf839031f47f6cb7d9e57233cb5
05 Affected products
06 References
- github.comhttps://github.com/FastCGI-Archives/fcgi2/issues/67
- github.comhttps://github.com/FastCGI-Archives/fcgi2/releases/tag/2.4.5
- www.synacktiv.comhttps://www.synacktiv.com/en/publications/cve-2025-23016-exploiting-the-fastcgi-library
- www.openwall.comhttp://www.openwall.com/lists/oss-security/2025/04/23/4
- lists.debian.orghttps://lists.debian.org/debian-lts-announce/2025/10/msg00009.html
07 Fixed in
Debian 12
- libfcgi Fixed in 2.4.2-2+deb12u1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- libfcgi Fixed in 2.4.5-0.1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- libfcgi Fixed in 2.4.5-0.1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 16.04 LTS
- libfcgi No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- libfcgi No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- libfcgi No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- libfcgi Fixed in 2.4.2-2ubuntu0.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- libfcgi Fixed in 2.4.2-2.1ubuntu0.24.04.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 25.10
- libfcgi Fixed in 2.4.5-0.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.