CVE-2025-40909: perl perl

Perl threads have a working directory race condition where file operations may target unintended paths

CVSS 5.9 MediumEPSS 0.0050 · 42nd percentile

Published by the CVE Program (CNA: CPANSec) at 30 May 2025, 12:20 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
perl	perl Package name: perl https://cpan.org/modules	affected 5.13.6 to before 5.41.13 custom Other versions: unaffected

Identifiers

CVE-2025-40909

CNA

CPANSec

Weakness (CWE)

CWE-426 · CWE-689

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
5.9	Medium	3.1	CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L	ADP (CISA-ADP)

CISA KEV Not listed.
EPSS 0.0050, the 42nd percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the CVE Program, published 30 May 2025. New records show when each source confirmed them.

Sources

References from the CNA

github.com/Perl/perl5/commit/918bfff86ca8d6d4e4ec5b30994451e0bd74aba9.patch patch
github.com/Perl/perl5/issues/23010 issue-tracking
bugs.debian.org/cgi-bin/bugreport.cgi?bug=1098226 related
github.com/Perl/perl5/issues/10387 related
perldoc.perl.org/5.14.0/perl5136delta#Directory-handles-not-copied-to-threads related
github.com/Perl/perl5/commit/11a11ecf4bea72b17d250cfb43c897be1341861e related
www.openwall.com/lists/oss-security/2025/05/22/2 mailing-listexploit

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.