{"id":"CVE-2026-53612","summary":"util-linux mount hook_owner TOCTOU allows local privilege escalation","details":"util-linux is a random collection of Linux utilities. In util-linux 2.39 through 2.41.4 and 2.42 through 2.42.1, the SUID `mount` utility's `hook_owner.c` post-mount hook performs path-based `chmod()` and `lchown()` operations on a previously validated mount target. A local low-privileged user authorized by an `/etc/fstab` entry with `user` or `users` and an `X-mount.mode`, `X-mount.owner`, or `X-mount.group` option can use `renameat2(RENAME_EXCHANGE)` to race a writable ancestor of the target and redirect the privileged ownership or mode change to a root-owned path, potentially gaining root privileges. This issue is fixed in 2.41.5 and 2.42.2.","aliases":["GHSA-g8wm-75wr-g2vh"],"modified":"2026-10-15T10:30:47.727385566Z","published":"2026-10-14T14:47:25.523Z","related":["SUSE-SU-2026:23250-1","SUSE-SU-2026:23255-1","SUSE-SU-2026:23861-1","SUSE-SU-2026:23870-1","SUSE-SU-2026:23884-1","SUSE-SU-2026:3684-1","SUSE-SU-2026:3685-1","openSUSE-SU-2026:11408-1","openSUSE-SU-2026:21905-1"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-367"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53612.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53612.json"},{"type":"FIX","url":"https://github.com/util-linux/util-linux/commit/24da33905c7115c4cbccd0afb2a469804e96467a"},{"type":"FIX","url":"https://github.com/util-linux/util-linux/commit/722c96974dd4009a334e4aee556eedaab5fb94b4"},{"type":"FIX","url":"https://github.com/util-linux/util-linux/commit/897a08c2b11dfa66975c3d24d63c7bf5f5be1a7c"},{"type":"FIX","url":"https://github.com/util-linux/util-linux/commit/d0c5adaeb3a3d823aba1377794de8f009b8152cc"},{"type":"WEB","url":"https://github.com/util-linux/util-linux/releases/tag/v2.41.5"},{"type":"WEB","url":"https://github.com/util-linux/util-linux/releases/tag/v2.42.2"},{"type":"ADVISORY","url":"https://github.com/util-linux/util-linux/security/advisories/GHSA-g8wm-75wr-g2vh"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53612"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/util-linux/util-linux","events":[{"introduced":"2dccaae42bfdd0f1e34da11f2023480655308e1b"},{"fixed":"230de59ffbee328506d92d3534e66d56de1afe5d"},{"introduced":"0a7dfc376192e8fb1e7bdb2d0c90d8b9b173a42b"},{"fixed":"f44509230b9f8224993b8c6157f85888359a64e1"}],"database_specific":{"extracted_events":[{"introduced":"2.39"},{"fixed":"2.41.5"},{"introduced":"2.42"},{"fixed":"2.42.2"}],"source":"AFFECTED_FIELD"}}],"versions":["v2.41.4","v2.42.1","v2.42","v2.42-rc2","v2.42-rc1","v2.41.3","v2.41.2","v2.41.2-rc1","v2.41.1","v2.41","v2.41-rc2","v2.41-rc1","v2.42-start"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53612.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:H/I:H/A:H"}]}