medium6.1
CVE-2026-112937
filelock: ReadWriteLock on the hard-link route deletes any directory another user renames onto its .filelock-* link directory name
Impact
filelock is a platform-independent file lock for Python. From 4.1.0 until 4.2.1, ReadWriteLock can remove a randomized .filelock-* private-hard-link directory during cleanup, allowing another local user with rename access in a non-sticky parent to observe a live name or forge a dead-owner sweep name and rename a sibling directory onto it for deletion. This issue is fixed in version 4.2.1.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | filelock | >= 4.1.0, <= 4.2.0 | 4.2.1 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Tox-Dev | Filelock | from 4.1.0 before 4.2.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-jqc4-5cvw-7w85
- https://github.com/tox-dev/filelock/security/advisories/GHSA-jqc4-5cvw-7w85
- https://nvd.nist.gov/vuln/detail/CVE-2026-112937
- https://github.com/tox-dev/filelock/pull/834
- https://github.com/tox-dev/filelock/commit/5e3f2ec0c5fb17cb2635b60b2b68bc63ab81ca2d
- https://github.com/tox-dev/filelock/releases/tag/4.2.1