🔐 CVE Alert

CVE-2026-112908

MEDIUM 5.3

filelock: StrictSoftFileLock creates its claim directories without the lock mode, so another local user with a write bit on them can end a live hold

CVSS Score
5.3
EPSS Score
0.0%
EPSS Percentile
0th

filelock is a platform-independent file lock for Python. From version 3.30.0 until version 4.2.1,  StrictSoftFileLock  and  AsyncStrictSoftFileLock  on POSIX systems create coordination and claim directories without applying the caller’s restrictive lock mode. A permissive umask or inherited default ACL can leave these directories writable by another local user, allowing that user to delete an active holder’s claims. Another authorized process can then acquire the lock while the original holder remains in its critical section. An attacker can also plant malformed claims to prevent acquisition. This issue is fixed in version 4.2.1.

CWE CWE-732
Vendor tox-dev
Product filelock
Published Nov 5, 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:L
Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
Low

Affected Versions

tox-dev / filelock
>= 3.30.0, < 4.2.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗
github.com: https://github.com/tox-dev/filelock/security/advisories/GHSA-6627-m3xw-93mp github.com: https://github.com/tox-dev/filelock/pull/839 github.com: https://github.com/tox-dev/filelock/commit/8cf51802158b9cf7e1fc560c2da30491a662cfde github.com: https://github.com/tox-dev/filelock/commit/bfa066d65a1ba9106f86ee9d027f7588b9c77e03 github.com: https://github.com/tox-dev/filelock/releases/tag/4.2.1