Cyber Resilience

CVE-2025-40907

MediumPublic PoC

Published: 16 May 2025

Published
16 May 2025
Modified
29 September 2025
KEV Added
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Patch
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CVSS Score v3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS Score 0.0076 73.7th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-40907 is a medium-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Fastcgi Fcgi. Its CVSS base score is 5.3 (Medium).

Operationally, ranked in the top 26.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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…

more

values in data to the IPC socket. This occurs in ReadParams in fcgiapp.c.

CWE(s)
CWE-122CWE-190

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

fastcgi
fcgi
0.44 — 0.82

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References