CVE-2026-112941

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.

CVSS 3.1

3.3CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

EPSS

0.1% chance of exploitation in the next 30 days; higher than 2% of CVEs (scores of 2026-10-25)

CWE

CWE-367

Published

2026-10-20

Modified

2026-10-21

Record from

the NVD, synced 2026-10-22

Affected

• tox-dev:filelock

References

• https://github.com/tox-dev/filelock/commit/bfa066d65a1ba9106f86ee9d027f7588b9c77e03
• https://github.com/tox-dev/filelock/pull/842
• https://github.com/tox-dev/filelock/releases/tag/4.2.1
• https://github.com/tox-dev/filelock/security/advisories/GHSA-wfhq-q4j2-c37m

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