{"id":"CVE-2026-112939","state":"PUBLISHED","title":"filelock: SoftFileLock removes a live holder's marker when another user forges the PID in a writable marker","description":"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.","publishedAt":"2026-10-20T14:38:52.373Z","updatedAt":"2026-10-20T15:14:56.836Z","severity":{"score":4.7,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["tox-dev filelock"],"affected":[{"vendor":"tox-dev","product":"filelock","versions":[{"version":">= 3.22.0, < 4.2.1","status":"affected"}]}],"references":["https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4","https://github.com/tox-dev/filelock/pull/836","https://github.com/tox-dev/filelock/commit/eeceaa846cbe4df72718d94c8371ca1ab8f5b3cc","https://github.com/tox-dev/filelock/releases/tag/4.2.1"],"weaknesses":["CWE-345"],"ingestedAt":"2026-10-29T20:10:43.281Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/112xxx/CVE-2026-112939.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-112939","state":"PUBLISHED","datePublished":"2026-10-20T14:38:52.373Z","dateUpdated":"2026-10-20T15:14:56.836Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-10-19T21:30:47.245Z"},"containers":{"cna":{"title":"filelock: SoftFileLock removes a live holder's marker when another user forges the PID in a writable marker","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"tox-dev","product":"filelock","versions":[{"version":">= 3.22.0, < 4.2.1","status":"affected"}]}],"references":[{"url":"https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4","name":"https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/tox-dev/filelock/pull/836","name":"https://github.com/tox-dev/filelock/pull/836","tags":["x_refsource_MISC"]},{"url":"https://github.com/tox-dev/filelock/commit/eeceaa846cbe4df72718d94c8371ca1ab8f5b3cc","name":"https://github.com/tox-dev/filelock/commit/eeceaa846cbe4df72718d94c8371ca1ab8f5b3cc","tags":["x_refsource_MISC"]},{"url":"https://github.com/tox-dev/filelock/releases/tag/4.2.1","name":"https://github.com/tox-dev/filelock/releases/tag/4.2.1","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"LOCAL","availabilityImpact":"NONE","baseScore":4.7,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-345","lang":"en","description":"CWE-345: Insufficient Verification of Data Authenticity","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-20T14:38:52.373Z"},"source":{"advisory":"GHSA-rfpc-qcw5-3pc4","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-20T15:14:32.481979Z","id":"CVE-2026-112939","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-20T15:14:56.836Z"}}]}}}