{"id":"CVE-2026-112939","summary":"filelock: SoftFileLock removes a live holder's marker when another user forges the PID in a writable marker","details":"filelock is a platform-independent file lock for Python. From 3.22.0 until 4.2.1, SoftFileLock can trust a forged process identifier in a marker that an attacker can modify but cannot remove, allowing an authorized contender such as another process of the holder's account or root to act as a confused deputy, remove the live marker, and admit another holder. This issue is fixed in version 4.2.1.","aliases":["GHSA-rfpc-qcw5-3pc4"],"modified":"2026-10-22T02:49:06.293901673Z","published":"2026-10-20T14:38:52.373Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-345"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/112xxx/CVE-2026-112939.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/112xxx/CVE-2026-112939.json"},{"type":"FIX","url":"https://github.com/tox-dev/filelock/commit/eeceaa846cbe4df72718d94c8371ca1ab8f5b3cc"},{"type":"FIX","url":"https://github.com/tox-dev/filelock/pull/836"},{"type":"WEB","url":"https://github.com/tox-dev/filelock/releases/tag/4.2.1"},{"type":"ADVISORY","url":"https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-112939"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/tox-dev/filelock","events":[{"introduced":"1dd2465cef7e5c189feaa16698a3ec3f33a653b0"},{"fixed":"60331bb89f325020b48bc51bde904c6446384e4a"},{"fixed":"eeceaa846cbe4df72718d94c8371ca1ab8f5b3cc"}],"database_specific":{"extracted_events":[{"source":"AFFECTED_FIELD","strategy":"StringRangeExpression","range":[{"introduced":"3.22.0"},{"fixed":"4.2.1"}]},{"source":"REFERENCES_COMMIT","range":[{"fixed":"eeceaa846cbe4df72718d94c8371ca1ab8f5b3cc"}]},{"source":"REFERENCES_TAG","original_tag":"4.2.1","range":[{"fixed":"60331bb89f325020b48bc51bde904c6446384e4a"}]}]}}],"versions":["4.2.0","4.1.2","4.1.1","4.1.0","4.0.12","4.0.11","4.0.10","4.0.9","4.0.8","4.0.7","4.0.6","4.0.5","4.0.4","4.0.3","4.0.2","4.0.1","4.0.0","3.32.7","3.32.6","3.32.5","3.32.4","3.32.3","3.32.2","3.32.1","3.32.0","3.31.2","3.31.1","3.31.0","3.30.3","3.30.2","3.30.1","3.30.0","3.29.7","3.29.6","3.29.5","3.29.4","3.29.3","3.29.2","3.29.1","3.29.0","3.28.0","3.27.0","3.26.1","3.26.0","3.25.2","3.25.1","3.25.0","3.24.4","3.24.3","3.24.2","3.24.1","3.24.0","3.23.0","3.22.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-112939.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N"}]}