medium4.7
CVE-2026-112906
filelock: SoftFileLock evicts a fresh lock file whose watched age another local user's pre-dated file passed on through inode reuse
Impact
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 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-2g95-wg33-c5x2
- https://github.com/tox-dev/filelock/security/advisories/GHSA-2g95-wg33-c5x2
- https://nvd.nist.gov/vuln/detail/CVE-2026-112906
- 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