filelock is a platform-independent file lock for Python. From 3.22.0 until 4.2.1, SoftFileLock can trust a forged process identifier in a marker that an attacker can modify but cannot remove, allowing an authorized contender such as another process of the holder's account or root to act as a confused deputy, remove the live marker, and admit another holder. This issue is fixed in version 4.2.1.
Fix
Patch, vendor advisory and mitigation references on NVD 4
- https://github.com/tox-dev/filelock/commit/eeceaa846cbe4df72718d94c8371ca1ab8f5b3cc Patch
- https://github.com/tox-dev/filelock/pull/836 Patch
- https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4 Exploit, Mitigation, Patch, Vendor Advisory
- https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4 Exploit, Mitigation, Patch, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 8
- Cpes+1 CPE criteria (now 1)NVD modified 2026-10-21 18:02
- StatusPublished → AnalyzedNVD modified 2026-10-21 18:02
- StatusUndergoing Analysis → PublishedNVD modified 2026-10-20 15:14
- StatusPublished → Undergoing AnalysisNVD modified 2026-10-20 19:48
- StatusReceived → PublishedNVD modified 2026-10-20 15:14
- StatusPublished → ReceivedNVD modified 2026-10-20 16:17
- StatusReceived → PublishedNVD modified 2026-10-20 14:38
- First seenCVSS 4.7NVD modified 2026-10-20 15:17
Affected (CPE criteria) 1
cpe:2.3:a:tox-dev:filelock:*:*:*:*:*:python:*:*
References 5
- https://github.com/tox-dev/filelock/commit/eeceaa846cbe4df72718d94c8371ca1ab8f5b3cc Patch
- https://github.com/tox-dev/filelock/pull/836 Patch
- https://github.com/tox-dev/filelock/releases/tag/4.2.1 Release Notes
- https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4 Exploit, Mitigation, Patch, Vendor Advisory
- https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4 Exploit, Mitigation, Patch, Vendor Advisory