CVE-2026-112911CWE-283

CVE-2026-112911

Medium · published October 20, 2026

CVSS v3.1
6.3
EPSS
0%
Percentile
1.1
In the wild
Unconfirmed
What it is

filelock is a platform-independent file lock for Python. From 3.30.0 until 4.2.1, StrictSoftFileLock versions from 3.30.0 and SoftReadWriteLock versions from 4.0.0 can adopt a protocol directory created first by another local user in a shared parent directory, allowing that user to alter protocol state and admit concurrent holders. This issue is fixed in version 4.2.1.

The record
Technical detail
CVSS v3.1
6.3 · MEDIUM
Vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00107 · 1.1th percentile
Weakness
CWE-283 · Unverified Ownership
Published
2026-10-20T19:17Z
Affected products (1)
ProductVersionsFixed in
tox-dev/filelock≥ 3.30.0, < 4.2.14.2.1
References (4)
https://github.com/tox-dev/filelock/commit/bfa066d65a1ba9106f86ee9d027f7588b9c77e03 · [email protected]https://github.com/tox-dev/filelock/pull/839 · [email protected]https://github.com/tox-dev/filelock/releases/tag/4.2.1 · [email protected]https://github.com/tox-dev/filelock/security/advisories/GHSA-9c4x-gm8v-wgc4 · [email protected]
EPSS history
Timeline
  • 22 OCT 03:29Z
    EPSS moved — → 0%
    epss
  • 20 OCT 14:21Z
    filelock: StrictSoftFileLock and SoftReadWriteLock adopt a protocol directory another user created first, losing mutual exclusion
    cvelistv5
  • 20 OCT 14:21Z
    filelock: StrictSoftFileLock and SoftReadWriteLock adopt a protocol directory another user created first, losing mutual exclusion
    cvelistv5