{"id":"CVE-2026-112909","summary":"filelock: UnixFileLock truncates and chmods any regular file another user renames or hard-links onto the lock path","details":"filelock is a platform-independent file lock for Python. Prior to 4.2.1, UnixFileLock can truncate a regular file renamed onto the lock path when another local user has actual rename permission, or hard-linked there under a permissive hard-link policy; when an explicit mode is requested, affected versions from 3.10.2 can also change that file's mode. This issue is fixed in version 4.2.1.","aliases":["GHSA-69hj-f68j-2879"],"modified":"2026-10-22T02:47:54.685899721Z","published":"2026-10-20T14:16:02.317Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/112xxx/CVE-2026-112909.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-706"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/112xxx/CVE-2026-112909.json"},{"type":"FIX","url":"https://github.com/tox-dev/filelock/commit/e1e825b1992f69fb6b346dc395d5ae4893536c0a"},{"type":"FIX","url":"https://github.com/tox-dev/filelock/pull/835"},{"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-69hj-f68j-2879"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-112909"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/tox-dev/filelock","events":[{"introduced":"0"},{"fixed":"60331bb89f325020b48bc51bde904c6446384e4a"},{"fixed":"e1e825b1992f69fb6b346dc395d5ae4893536c0a"}],"database_specific":{"extracted_events":[{"strategy":"StringRangeExpression","range":[{"introduced":"0"},{"fixed":"4.2.1"}],"source":"AFFECTED_FIELD"},{"source":"REFERENCES_COMMIT","range":[{"fixed":"e1e825b1992f69fb6b346dc395d5ae4893536c0a"}]},{"original_tag":"4.2.1","range":[{"fixed":"60331bb89f325020b48bc51bde904c6446384e4a"}],"source":"REFERENCES_TAG"}]}}],"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","3.21.2","3.21.1","3.21.0","3.20.3","3.20.2","3.20.1","3.20.0","3.19.1","3.19.0","3.18.0","3.17.0","3.16.1","3.16.0","3.15.4","3.15.3","3.15.2","3.15.1","3.15.0","3.14.0","3.13.4","3.13.3","3.13.2","3.13.1","3.13.0","3.12.4","3.12.3","3.12.2","3.12.1","3.12.0","3.11.0","3.10.7","3.10.6","3.10.5","3.10.4","3.10.3","3.10.2","3.10.1","3.10.0","3.9.1","3.9.0","3.8.2","3.8.1","3.8.0","3.7.1","3.7.0","3.6.0","3.5.1","3.5.0","3.4.2","3.4.1","3.4.0","3.3.2","3.3.1","3.3.0","3.2.1","3.2.0","3.1.0","v3.0.12","v3.0.10","v3.0.9","v3.0.8","v3.0.7","v3.0.6","v3.0.4","v3.0.3","v3.0.1","v3.0.0","v2.0.13","v2.0.12","v2.0.11","v2.0.10","v2.0.9","v2.0.8","v2.0.7","v2.0.6","v2.0.5","v2.0.4","v2.0.3","v2.0.2","v2.0.1","v2.0.0","v1.0.3","v1.0.2","v1.0.1","v1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-112909.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N"}]}