GHSA-m462-7rxw-wvpg: filelock (CVE-2026-112938)

Package	Ecosystem	Affected	Fixed in
filelock	PyPI	>=3.30.0, <4.2.1	4.2.1

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

filelock versions 3.30.0 through 4.2.0 are vulnerable in StrictSoftFileLock and AsyncStrictSoftFileLock, which can follow a symbolic link placed in the lock's coordination directory. A local user with an account who can rename that directory, which depends on the directory's permissions, can make the lock create claim files in a directory they choose, and this can block other processes from taking the lock. Upgrade to filelock 4.2.1, the fixed version. The source text is cut off in places.

Written 31 Oct 2026.

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

Score	Rating	CVSS	Vector	Source
5.8	Medium	3.1	CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H	CNA (GitHub_M)

CISA KEV Not listed.
EPSS No score.

Timeline

31 Oct 2026, 14:07 UTC First seen by agentprime
31 Oct 2026, 14:07 UTC Confirmed by OSV
5 Nov 2026, 21:51 UTC Confirmed by the CVE List
5 Nov 2026, 22:17 UTC Confirmed by NVD

Sources

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.