Medium 6.1Published Oct 20, 2026

CVE-2026-112937filelock: ReadWriteLock on the hard-link route deletes any directory another user renames onto its .filelock-* link directory name

Updated under an hour ago (Oct 28, 2026, 3:30 AM ET)

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It affects tox-dev filelock and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for tox-dev filelock

Exploited in the last 30 days

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.

CVSS: 6.1 MEDIUM (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
Weakness (CWE): CWE-367
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Oct 21, 2026
First seen by InfoSec Signals: Oct 20, 2026

Affected products

Affected products

tox-dev filelock tox_dev:filelock (from the name)	from 4.1.0, < 4.2.1	CNA record
tox-dev filelock tox-dev:filelock	from 4.1.0 before 4.2.1	NVD

References

References

https://github.com/tox-dev/filelock/security/advisories/GHSA-jqc4-5cvw-7w85	x-refsource-confirm, exploit, mitigation, patch, vendor-advisory
https://github.com/tox-dev/filelock/pull/834	x-refsource-misc, patch
https://github.com/tox-dev/filelock/commit/5e3f2ec0c5fb17cb2635b60b2b68bc63ab81ca2d	x-refsource-misc, patch
https://github.com/tox-dev/filelock/releases/tag/4.2.1	x-refsource-misc, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.