medium5.3
CVE-2026-112914
filelock: SoftFileLock stale-break restore follows a swapped-in symbolic link and hard-links a file of the user running the lock into the lock directory
Impact
filelock is a platform-independent file lock for Python. From 4.1.0 until 4.2.1, SoftFileLock can restore a stale marker by name after moving it aside, allowing another local user with rename access in a non-sticky lock directory to swap in a symbolic link and, on a runtime that follows the link and a same-filesystem target, make the lock user hard-link one of its files into the lock directory. 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-crv4-6mhj-j5jh
- https://github.com/tox-dev/filelock/security/advisories/GHSA-crv4-6mhj-j5jh
- https://nvd.nist.gov/vuln/detail/CVE-2026-112914
- https://github.com/tox-dev/filelock/pull/843
- https://github.com/tox-dev/filelock/commit/740ff666b62a88496c8d7394e4e6230605e4d62b
- https://github.com/tox-dev/filelock/releases/tag/4.2.1