CVE-2026-112935
filelock: SoftFileLock stale-lock break removes a live lock file on a reused inode number and admits two holders
CVSS Score
4.7
EPSS Score
0.0%
EPSS Percentile
0th
filelock is a platform-independent file lock for Python. From 3.22.0 until 4.2.1, SoftFileLock can break a stale marker after an attacker frees its own marker following the stale read, an honest contender creates a live successor on the reused inode, and the successor's modification time is not newer than the saved observation, causing the live marker to be removed and two holders to be admitted. This issue is fixed in version 4.2.1.
| CWE | CWE-367 |
| 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:N Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None
Affected Versions
tox-dev / filelock
>= 3.22.0, < 4.2.1
References
github.com: https://github.com/tox-dev/filelock/security/advisories/GHSA-fq56-3cx3-fjxp github.com: https://github.com/tox-dev/filelock/pull/843 github.com: https://github.com/tox-dev/filelock/commit/740ff666b62a88496c8d7394e4e6230605e4d62b github.com: https://github.com/tox-dev/filelock/releases/tag/4.2.1