Description
filelock is a platform-independent file lock for Python. From 3.20.4 until 4.0.9, ReadWriteLock and AsyncReadWriteLock versions from 3.20.4 resolve the lock path and pass it to SQLite without rejecting a final symbolic link, allowing another local user who can create names in the lock directory to redirect database creation and locking or split mutual exclusion between targets. This issue is fixed in version 4.0.9.
Affected products
tox-dev: filelock
References4
- github.com/tox-dev/filelock/security/advisories/GHSA-j8f7-rjxc-… ExploitVendor Advisory
- github.com/tox-dev/filelock/security/advisories/GHSA-j8f7-rjxc-… ExploitVendor Advisory
- github.com/tox-dev/filelock/commit/4d45e83caf7e31f9a12fb44526bd… Patch
- github.com/tox-dev/filelock/releases/tag/4.0.9 Release Notes
Metrics
- CVSS 3.1
-
6.1
MEDIUM
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L - EPSS — exploit probability
- 0% percentile: 14 · as of 9 November 2026
- CWE
- CWE-59CWE-668
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.