Description
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.
Affected products
tox-dev: filelock
References4
- github.com/tox-dev/filelock/security/advisories/GHSA-2g95-wg33-… ExploitMitigationPatchVendor Advisory
- github.com/tox-dev/filelock/security/advisories/GHSA-2g95-wg33-… ExploitMitigationPatchVendor Advisory
- github.com/tox-dev/filelock/commit/740ff666b62a88496c8d7394e4e6… Patch
- github.com/tox-dev/filelock/releases/tag/4.2.1 Release Notes
Metrics
- CVSS 3.1
-
4.7
MEDIUM
Score source: CNA
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N - EPSS — exploit probability
- 0% percentile: 6 · as of 9 November 2026
- CWE
- CWE-694CWE-362
Could this be exploited in your environment?
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