CVE-2025-40909
Perl threads have a working directory race condition where file operations may target unintended paths
CVSS Score
5.9
EPSS Score
0.0%
EPSS Percentile
10th
Perl threads have a working directory race condition where file operations may target unintended paths. If a directory handle is open at thread creation, the process-wide current working directory is temporarily changed in order to clone that handle for the new thread, which is visible from any third (or more) thread already running. This may lead to unintended operations such as loading code or accessing files from unexpected locations, which a local attacker may be able to exploit. The bug was introduced in commit 11a11ecf4bea72b17d250cfb43c897be1341861e and released in Perl version 5.13.6
| CWE | CWE-689 CWE-426 |
| Vendor | perl |
| Product | perl |
| Published | May 30, 2025 |
| Last Updated | Apr 18, 2026 |
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Affected Versions
perl / perl
5.13.6 < 5.41.13
References
github.com: https://github.com/Perl/perl5/commit/918bfff86ca8d6d4e4ec5b30994451e0bd74aba9.patch openwall.com: https://www.openwall.com/lists/oss-security/2025/05/22/2 github.com: https://github.com/Perl/perl5/issues/23010 bugs.debian.org: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1098226 github.com: https://github.com/Perl/perl5/issues/10387 perldoc.perl.org: https://perldoc.perl.org/5.14.0/perl5136delta#Directory-handles-not-copied-to-threads github.com: https://github.com/Perl/perl5/commit/11a11ecf4bea72b17d250cfb43c897be1341861e openwall.com: http://www.openwall.com/lists/oss-security/2025/05/23/1 openwall.com: http://www.openwall.com/lists/oss-security/2025/05/30/4 openwall.com: http://www.openwall.com/lists/oss-security/2025/06/02/2 openwall.com: http://www.openwall.com/lists/oss-security/2025/06/02/5 openwall.com: http://www.openwall.com/lists/oss-security/2025/06/02/6 openwall.com: http://www.openwall.com/lists/oss-security/2025/06/02/7 openwall.com: http://www.openwall.com/lists/oss-security/2025/06/03/1 seclists.org: http://seclists.org/fulldisclosure/2025/Sep/55 seclists.org: http://seclists.org/fulldisclosure/2025/Sep/54 seclists.org: http://seclists.org/fulldisclosure/2025/Sep/53 lists.debian.org: https://lists.debian.org/debian-lts-announce/2026/04/msg00018.html
Credits
Vincent Lefevre