All vulnerabilities
CVE-2026-112915GHSA-cwqr-hh33-gh44

filelock ReadWriteLock: a crafted lock database makes every acquire stall or hang regardless of timeout

tox-dev filelock
Open in ThreatlineRecord JSON
CVSS
5.5Medium
ExploitationPublic exploit codeCISA's assessment says proof of concept code is public, assessed 20 Oct 2026. Not in the KEV catalogCISA via CVE List
Exploit odds (EPSS)0.22%Chance of exploitation activity in the next 30 days, higher than 11% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in4.2.1Fixed versionGitHub
Published20 Oct 2026Updated 20 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

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.

Text from CVE List

Affected versions 2

  • filelockaffected: >= 3.20.4, < 4.2.1CVE List
  • filelock, pip>= 3.20.4, <= 4.2.0GitHub

References 4