Vulnerability · Published Oct 20, 2026 · Assigned by GitHub_M
CVE-2026-112915filelock ReadWriteLock: a crafted lock database makes every acquire stall or hang regardless of timeout
Medium 5.5
In plain English
A medium-severity uncontrolled resource consumption in filelock from tox-dev. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
filelock is a platform-independent file lock for Python. From 3.20.4 until 4.2.1, ReadWriteLock can open a crafted SQLite lock database without bounding schema and query work, allowing another local user who can replace the database to make acquisition stall or hang; versions from 3.20.4 expose this on initial per-instance opening, and versions from 3.30.0 repeat the exposure on every acquisition. This issue is fixed in version 4.2.1.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | python-filelock | no fix listed | DEBIAN-CVE-2026-112915 |
| Debian:13 | python-filelock | no fix listed | DEBIAN-CVE-2026-112915 |
| Debian:14 | python-filelock | no fix listed | DEBIAN-CVE-2026-112915 |
| PyPI | filelock | 4.2.1 | GHSA-cwqr-hh33-gh44 |
| Ubuntu:26.04:LTS | python-filelock | no fix listed | UBUNTU-CVE-2026-112915 |
| Ubuntu:26.10 | python-filelock | no fix listed | UBUNTU-CVE-2026-112915 |
Affected products (as reported)
Weakness: CWE-400 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/tox-dev/filelock/security/advisories/GHSA-cwqr-hh33-gh44 x_refsource_CONFIRM
- https://github.com/tox-dev/filelock/pull/834 x_refsource_MISC
- https://github.com/tox-dev/filelock/commit/5e3f2ec0c5fb17cb2635b60b2b68bc63ab81ca2d x_refsource_MISC
- https://github.com/tox-dev/filelock/releases/tag/4.2.1 x_refsource_MISC