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

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

• CISA KEV Not listed.
• EPSS 0.0022, the 12th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 31 Oct 2026, 14:07 UTC First seen by agentprime
2. 31 Oct 2026, 14:07 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-cwqr-hh33-gh44
• OSV: GHSA-cwqr-hh33-gh44
• github.com/tox-dev/filelock/security/advisories/GHSA-cwqr-hh33-gh44
• nvd.nist.gov/vuln/detail/CVE-2026-112915
• github.com/tox-dev/filelock/pull/834
• github.com/tox-dev/filelock/commit/5e3f2ec0c5fb17cb2635b60b2b68bc63ab81ca2d
• github.com/tox-dev/filelock
• github.com/tox-dev/filelock/releases/tag/4.2.1

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.