CVE-2026-112937

MEDIUM 6.1

filelock: ReadWriteLock on the hard-link route deletes any directory another user renames onto its .filelock-* link directory name

CVSS Score

6.1

EPSS Score

0.0%

EPSS Percentile

0th

filelock is a platform-independent file lock for Python. From 4.1.0 until 4.2.1, ReadWriteLock can remove a randomized .filelock-* private-hard-link directory during cleanup, allowing another local user with rename access in a non-sticky parent to observe a live name or forge a dead-owner sweep name and rename a sibling directory onto it for deletion. This issue is fixed in version 4.2.1.

CWE	CWE-367
Vendor	tox-dev
Product	filelock
Published	Oct 20, 2026

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CVSS v3 Breakdown

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

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

Low

Affected Versions

tox-dev / filelock

>= 4.1.0, < 4.2.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/tox-dev/filelock/security/advisories/GHSA-jqc4-5cvw-7w85 github.com: https://github.com/tox-dev/filelock/pull/834 github.com: https://github.com/tox-dev/filelock/commit/5e3f2ec0c5fb17cb2635b60b2b68bc63ab81ca2d github.com: https://github.com/tox-dev/filelock/releases/tag/4.2.1