filelock is a platform-independent file lock for Python. From 4.1.0 until 4.2.1, SoftFileLock versions from 4.1.0 can reuse a stale observation when an attacker pre-dates and removes its own marker, at least two lock-user processes are waiting, coarse or matching modification times preserve the observation, and an honest contender creates a fresh marker on the reused inode, causing that live marker to be removed as stale. This issue is fixed in version 4.2.1.
Fix
Patch, vendor advisory and mitigation references on NVD 3
- https://github.com/tox-dev/filelock/commit/740ff666b62a88496c8d7394e4e6230605e4d62b Patch
- https://github.com/tox-dev/filelock/security/advisories/GHSA-2g95-wg33-c5x2 Exploit, Mitigation, Patch, Vendor Advisory
- https://github.com/tox-dev/filelock/security/advisories/GHSA-2g95-wg33-c5x2 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 9
- CwesCWE-694 → CWE-694, CWE-362NVD modified 2026-10-27 21:06
- Cpes+1 CPE criteria (now 1)NVD modified 2026-10-27 21:06
- StatusPublished → AnalyzedNVD modified 2026-10-27 21:06
- StatusUndergoing Analysis → PublishedNVD modified 2026-10-20 15:27
- StatusPublished → Undergoing AnalysisNVD modified 2026-10-20 19:48
- StatusReceived → PublishedNVD modified 2026-10-20 15:27
- StatusPublished → ReceivedNVD modified 2026-10-20 16:17
- StatusReceived → PublishedNVD modified 2026-10-20 14:09
- First seenCVSS 4.7NVD modified 2026-10-20 15:17
Affected (CPE criteria) 1
cpe:2.3:a:tox-dev:filelock:*:*:*:*:*:python:*:*
References 4
- https://github.com/tox-dev/filelock/commit/740ff666b62a88496c8d7394e4e6230605e4d62b Patch
- https://github.com/tox-dev/filelock/releases/tag/4.2.1 Release Notes
- https://github.com/tox-dev/filelock/security/advisories/GHSA-2g95-wg33-c5x2 Exploit, Mitigation, Patch, Vendor Advisory
- https://github.com/tox-dev/filelock/security/advisories/GHSA-2g95-wg33-c5x2 Exploit, Mitigation, Patch, Vendor Advisory