CVE-2026-112908
filelock: StrictSoftFileLock creates its claim directories without the lock mode, so another local user with a write bit on them can end a live hold
filelock is a platform-independent file lock for Python. From version 3.30.0 until version 4.2.1, StrictSoftFileLock and AsyncStrictSoftFileLock on POSIX systems create coordination and claim directories without applying the caller’s restrictive lock mode. A permissive umask or inherited default ACL can leave these directories writable by another local user, allowing that user to delete an active holder’s claims. Another authorized process can then acquire the lock while the original holder remains in its critical section. An attacker can also plant malformed claims to prevent acquisition. This issue is fixed in version 4.2.1.
Fixes and workarounds
Fix
filelock (PyPI): OSV reports a fixed version 4.2.1. Check the advisory for supported release branches.
Source: OSV GHSA-6627-m3xw-93mpAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| filelock tox-dev |
>= 3.30.0, < 4.2.1 (affected) | CNA: GitHub_M |
filelockfilelock
PyPI |
3.30.0 (affected, PyPI) 3.30.1 (affected, PyPI) 3.30.2 (affected, PyPI) 3.30.3 (affected, PyPI) 3.31.0 (affected, PyPI) 3.31.1 (affected, PyPI) 3.31.2 (affected, PyPI) 3.32.0 (affected, PyPI) 3.32.2 (affected, PyPI) 3.32.3 (affected, PyPI) 3.32.4 (affected, PyPI) 3.32.5 (affected, PyPI) 3.32.6 (affected, PyPI) 3.32.7 (affected, PyPI) 4.0.0 (affected, PyPI) 4.0.1 (affected, PyPI) 4.0.10 (affected, PyPI) 4.0.11 (affected, PyPI) 4.0.12 (affected, PyPI) 4.0.2 (affected, PyPI) 4.0.3 (affected, PyPI) 4.0.4 (affected, PyPI) 4.0.5 (affected, PyPI) 4.0.6 (affected, PyPI) 4.0.7 (affected, PyPI) 4.0.8 (affected, PyPI) 4.0.9 (affected, PyPI) 4.1.0 (affected, PyPI) 4.1.1 (affected, PyPI) 4.1.2 (affected, PyPI) 4.2.0 (affected, PyPI) Ecosystem version events: introduced 3.30.0; fixed 4.2.1 Source events (ECOSYSTEM)Other versions: unaffected |
OSV GHSA-6627-m3xw-93mp |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 5.3 medium |
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L | CNA: GitHub_M |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/tox-dev/filelock/security/advisories/GHSA-6627-m3xw-93mpCNA: GitHub_M · x_refsource_CONFIRM
- https://github.com/tox-dev/filelock/pull/839CNA: GitHub_M · x_refsource_MISC
- https://github.com/tox-dev/filelock/commit/8cf51802158b9cf7e1fc560c2da30491a662cfdeCNA: GitHub_M · x_refsource_MISC
- https://github.com/tox-dev/filelock/commit/bfa066d65a1ba9106f86ee9d027f7588b9c77e03CNA: GitHub_M · x_refsource_MISC
- https://github.com/tox-dev/filelock/releases/tag/4.2.1CNA: GitHub_M · x_refsource_MISC
- https://github.com/advisories/GHSA-6627-m3xw-93mpOSV / GitHub Security Advisories · advisory
- https://osv.dev/vulnerability/GHSA-6627-m3xw-93mpOSV / GitHub Security Advisories · osv
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