CVE-2026-112937CWE-367

CVE-2026-112937

Medium · published October 20, 2026

CVSS v3.1
6.1
EPSS
0%
Percentile
0.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.1 · MEDIUM
Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
CVSS v4.0
Not supplied
EPSS
0.00096 · 0.7th percentile
Weakness
CWE-367 · Time-of-check Time-of-use (TOCTOU) Race Condition
Published
2026-10-20T19:17Z
Affected products (1)
ProductVersionsFixed in
tox-dev/filelock≥ 4.1.0, < 4.2.14.2.1
References (4)
https://github.com/tox-dev/filelock/commit/5e3f2ec0c5fb17cb2635b60b2b68bc63ab81ca2d · [email protected]https://github.com/tox-dev/filelock/pull/834 · [email protected]https://github.com/tox-dev/filelock/releases/tag/4.2.1 · [email protected]https://github.com/tox-dev/filelock/security/advisories/GHSA-jqc4-5cvw-7w85 · [email protected]
EPSS history
Timeline
  • 22 OCT 03:29Z
    EPSS moved — → 0%
    epss
  • 20 OCT 14:36Z
    filelock: ReadWriteLock on the hard-link route deletes any directory another user renames onto its .filelock-* link directory name
    cvelistv5
  • 20 OCT 14:36Z
    filelock: ReadWriteLock on the hard-link route deletes any directory another user renames onto its .filelock-* link directory name
    cvelistv5