How severe is CVE-2025-23016?

CVE-2025-23016 has a CVSS 3.x base score of 9.3, rated critical severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-23016 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-23016?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2025-23016 have an EU (EUVD) identifier?

Yes. CVE-2025-23016 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-3075.

When was CVE-2025-23016 published?

CVE-2025-23016 was published on 2025-01-10 and last updated on 2026-06-17.

CVE-2025-23016

CVE-2025-23016 is a critical-severity vulnerability with a CVSS 3.x base score of 9.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-190.

Key facts

Severity: Critical (CVSS 3.x base score 9.3)
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-3075
Weakness: CWE-190
Published: 2025-01-10
Last modified: 2026-06-17

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.

Frequently asked questions

What is 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 ReadParams in fcgiapp.c.
How severe is CVE-2025-23016?: CVE-2025-23016 has a CVSS 3.x base score of 9.3, rated critical severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-23016 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-23016?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-23016 have an EU (EUVD) identifier?: Yes. CVE-2025-23016 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-3075.
When was CVE-2025-23016 published?: CVE-2025-23016 was published on 2025-01-10 and last updated on 2026-06-17.

References

Other CWE-190 (Integer Overflow or Wraparound) vulnerabilities

CVE-2026-4689 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability was…
CVE-2026-24814 — Critical (CVSS 10.0): Integer Overflow or Wraparound vulnerability in swoole swoole-src (thirdparty/hiredis modules). This vulnerability is…
CVE-2025-64721 — Critical (CVSS 10.0): Sandboxie is a sandbox-based isolation software for 32-bit and 64-bit Windows NT-based operating systems. In versions…
CVE-2015-5108 — Critical (CVSS 10.0): Integer overflow in Adobe Reader and Acrobat 10.x before 10.1.15 and 11.x before 11.0.12, Acrobat and Acrobat Reader DC…
CVE-2015-5097 — Critical (CVSS 10.0): Integer overflow in Adobe Reader and Acrobat 10.x before 10.1.15 and 11.x before 11.0.12, Acrobat and Acrobat Reader DC…
CVE-2013-2555 — Critical (CVSS 10.0): Integer overflow in Adobe Flash Player before 10.3.183.75 and 11.x before 11.7.700.169 on Windows and Mac OS X, before…

Browse all CWE-190 (Integer Overflow or Wraparound) vulnerabilities →