CVE-2026-112911
filelock: StrictSoftFileLock and SoftReadWriteLock adopt a protocol directory another user created first, losing mutual exclusion
CVSS Score
6.3
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-283 |
| Vendor | tox-dev |
| Product | filelock |
| Published | Oct 20, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
High
Affected Versions
tox-dev / filelock
>= 3.30.0, < 4.2.1
References
github.com: https://github.com/tox-dev/filelock/security/advisories/GHSA-9c4x-gm8v-wgc4 github.com: https://github.com/tox-dev/filelock/pull/839 github.com: https://github.com/tox-dev/filelock/commit/bfa066d65a1ba9106f86ee9d027f7588b9c77e03 github.com: https://github.com/tox-dev/filelock/releases/tag/4.2.1