CVE-2026-112941

Name	CVE-2026-112941
Description	filelock is a platform-independent file lock for Python. From 4.1.0 until 4.2.1, SoftReadWriteLock and AsyncSoftReadWriteLock cache a successful check of the <path>.rw lock tree and resolve its names again during later record operations, allowing another local user who can replace that tree after the first acquisition to redirect lock-record writes into directories writable by the lock user. This issue is fixed in version 4.2.1.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
python-filelock (PTS)	bookworm	3.9.0-1+deb12u1	vulnerable
	trixie	3.18.0-1+deb13u1	vulnerable
	forky	4.0.1-1	vulnerable
	sid	4.1.1-1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
python-filelock	source	(unstable)	(unfixed)

Notes

https://github.com/tox-dev/filelock/security/advisories/GHSA-wfhq-q4j2-c37m
https://github.com/tox-dev/filelock/pull/842
Fixed by: https://github.com/tox-dev/filelock/commit/bfa066d65a1ba9106f86ee9d027f7588b9c77e03 (4.2.1)