{"id":"CVE-2026-112912","state":"PUBLISHED","title":"filelock: Symlink swap during SoftFileLock's writability check leaks whether a path exists and is writable by the lock taker","description":"filelock is a platform-independent file lock for Python. From 3.32.6 until 4.2.1, SoftFileLock can follow a swapped symbolic link during the conditional os.access writability check for a node without its owner-write bit, allowing another local user on a platform and directory configuration that follows the link to infer whether a chosen path exists and is writable from the observable acquisition result. This issue is fixed in version 4.2.1.","publishedAt":"2026-10-20T14:23:18.993Z","updatedAt":"2026-10-20T15:37:56.208Z","severity":{"score":2.5,"label":"Low","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["tox-dev filelock"],"affected":[{"vendor":"tox-dev","product":"filelock","versions":[{"version":">= 3.32.6, < 4.2.1","status":"affected"}]}],"references":["https://github.com/tox-dev/filelock/security/advisories/GHSA-9j6q-wvj5-jgjg","https://github.com/tox-dev/filelock/pull/835","https://github.com/tox-dev/filelock/commit/e1e825b1992f69fb6b346dc395d5ae4893536c0a","https://github.com/tox-dev/filelock/releases/tag/4.2.1"],"weaknesses":["CWE-59"],"ingestedAt":"2026-10-29T20:10:43.281Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/112xxx/CVE-2026-112912.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-112912","state":"PUBLISHED","datePublished":"2026-10-20T14:23:18.993Z","dateUpdated":"2026-10-20T15:37:56.208Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-10-19T20:16:09.858Z"},"containers":{"cna":{"title":"filelock: Symlink swap during SoftFileLock's writability check leaks whether a path exists and is writable by the lock taker","descriptions":[{"lang":"en","value":"filelock is a platform-independent file lock for Python. From 3.32.6 until 4.2.1, SoftFileLock can follow a swapped symbolic link during the conditional os.access writability check for a node without its owner-write bit, allowing another local user on a platform and directory configuration that follows the link to infer whether a chosen path exists and is writable from the observable acquisition result. This issue is fixed in version 4.2.1."}],"affected":[{"vendor":"tox-dev","product":"filelock","versions":[{"version":">= 3.32.6, < 4.2.1","status":"affected"}]}],"references":[{"url":"https://github.com/tox-dev/filelock/security/advisories/GHSA-9j6q-wvj5-jgjg","name":"https://github.com/tox-dev/filelock/security/advisories/GHSA-9j6q-wvj5-jgjg","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/tox-dev/filelock/pull/835","name":"https://github.com/tox-dev/filelock/pull/835","tags":["x_refsource_MISC"]},{"url":"https://github.com/tox-dev/filelock/commit/e1e825b1992f69fb6b346dc395d5ae4893536c0a","name":"https://github.com/tox-dev/filelock/commit/e1e825b1992f69fb6b346dc395d5ae4893536c0a","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":2.5,"baseSeverity":"LOW","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-59","lang":"en","description":"CWE-59: Improper Link Resolution Before File Access ('Link Following')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-20T14:23:18.993Z"},"source":{"advisory":"GHSA-9j6q-wvj5-jgjg","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/tox-dev/filelock/security/advisories/GHSA-9j6q-wvj5-jgjg","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-20T15:37:27.795354Z","id":"CVE-2026-112912","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":"2026-10-20T15:37:56.208Z"}}]}}}