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.
Metrics
Affected Vendors & Products
References
History
Fri, 06 Nov 2026 12:15:00 +0000
| Type | Values Removed | Values Added |
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| Weaknesses | CWE-279 | |
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threat_severity
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threat_severity
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Fri, 06 Nov 2026 00:00:00 +0000
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Tox-dev
Tox-dev filelock |
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| Vendors & Products |
Tox-dev
Tox-dev filelock |
Thu, 05 Nov 2026 22:15:00 +0000
| Type | Values Removed | Values Added |
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| Description | 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. | |
| Title | 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 | |
| Weaknesses | CWE-732 | |
| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-11-05T21:54:53.585Z
Updated: 2026-11-05T21:54:53.585Z
Reserved: 2026-10-19T20:16:09.857Z
Link: CVE-2026-112908
No data.
Status : Awaiting Analysis
Published: 2026-11-05T22:17:46.693
Modified: 2026-11-06T21:40:43.450
Link: CVE-2026-112908