CVE-2025-40909
Perl threads have a working directory race condition where file operations may target unintended paths
At a glance
- Severity
- MEDIUM 5.9
- EPSS
- EPSS 0.50 % · percentile 43 (2026-10-27)
- State
- PUBLISHED
- Published
- Updated
- Assigner
- CPANSec
- NVD status
- Deferred
Description
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
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.9 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L | CISA-ADP |
| CVSS 3.1 | MEDIUM 5.9 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L | NVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary) |
Weaknesses (CWE)
European references
- ENISA EUVD · EUVD-2025-16506
- GCVE · GCVE-0-2025-40909
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0810 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0424 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0218 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0969 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0947 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0864 — Multiples vulnérabilités dans VMware Tanzu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0791 — Multiples vulnérabilités dans les produits Apple · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0756 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| perl · perl | affected 5.13.6 < 5.41.13 |
References
- https://github.com/Perl/perl5/commit/918bfff86ca8d6d4e4ec5b30994451e0bd74aba9.patch
- https://www.openwall.com/lists/oss-security/2025/05/22/2
- https://github.com/Perl/perl5/issues/23010
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1098226
- https://github.com/Perl/perl5/issues/10387
- https://perldoc.perl.org/5.14.0/perl5136delta#Directory-handles-not-copied-to-threads
- https://github.com/Perl/perl5/commit/11a11ecf4bea72b17d250cfb43c897be1341861e
- http://www.openwall.com/lists/oss-security/2025/05/23/1
- http://www.openwall.com/lists/oss-security/2025/05/30/4
- http://www.openwall.com/lists/oss-security/2025/06/02/2
- http://www.openwall.com/lists/oss-security/2025/06/02/5
- http://www.openwall.com/lists/oss-security/2025/06/02/6
- http://www.openwall.com/lists/oss-security/2025/06/02/7
- http://www.openwall.com/lists/oss-security/2025/06/03/1
- http://seclists.org/fulldisclosure/2025/Sep/55
- http://seclists.org/fulldisclosure/2025/Sep/54
- http://seclists.org/fulldisclosure/2025/Sep/53
- https://lists.debian.org/debian-lts-announce/2026/04/msg00018.html
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |