CVE-2026-112908
Dashboard / Vulnerabilities / CVE-2026-112908
Summary: 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
Details: 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.
References: https://github.com/tox-dev/filelock/releases/tag/4.2.1, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/112xxx/CVE-2026-112908.json, https://github.com/tox-dev/filelock/security/advisories/GHSA-6627-m3xw-93mp, https://nvd.nist.gov/vuln/detail/CVE-2026-112908, https://github.com/tox-dev/filelock/commit/8cf51802158b9cf7e1fc560c2da30491a662cfde, https://github.com/tox-dev/filelock/commit/bfa066d65a1ba9106f86ee9d027f7588b9c77e03, https://github.com/tox-dev/filelock/pull/839
Affected packages
Package
Name:
Purl:
Affected ranges
Type: GIT
Events:
