{"id":"CVE-2026-112912","title":"filelock: Symlink swap during SoftFileLock's writability check leaks whether a path exists and is writable by the lock taker","summary":"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…","severity":"low","cvss":2.5,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N","cvssSource":"cna","cwe":["CWE-59"],"vendor":"tox-dev","product":"filelock","affected":["filelock >= 3.32.6, < 4.2.1"],"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-20T15:37:27.795354Z"},"exploitAvailable":true,"published":"2026-10-20","updated":"2026-10-20","sourceUpdated":"2026-10-20T15:37:56.208Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-112912","references":[{"url":"https://github.com/tox-dev/filelock/security/advisories/GHSA-9j6q-wvj5-jgjg","label":"https://github.com/tox-dev/filelock/security/advisories/GHSA-9j6q-wvj5-jgjg"},{"url":"https://github.com/tox-dev/filelock/pull/835","label":"https://github.com/tox-dev/filelock/pull/835"},{"url":"https://github.com/tox-dev/filelock/commit/e1e825b1992f69fb6b346dc395d5ae4893536c0a","label":"https://github.com/tox-dev/filelock/commit/e1e825b1992f69fb6b346dc395d5ae4893536c0a"},{"url":"https://github.com/tox-dev/filelock/releases/tag/4.2.1","label":"https://github.com/tox-dev/filelock/releases/tag/4.2.1"}],"tags":["cve.org","exploit-available"],"ingestedAt":"2026-10-20T15:09:24.126Z","slug":"CVE-2026-112912","body":"## Overview\n\nfilelock 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.\n\n## Affected\n\n- `filelock >= 3.32.6, < 4.2.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":26,"depthScoreParts":{"impact":13.8,"likelihood":0,"exploitation":12,"ransomware":0},"changes":[{"seq":225960,"id":"CVE-2026-112912","ts":1792512719541,"field":"exploit_available","old":"false","new":"true"}]}