{"id":"CVE-2026-53613","state":"PUBLISHED","title":"util-linux mount target TOCTOU allows local privilege escalation","description":"util-linux is a random collection of Linux utilities. In util-linux 2.17 through 2.41.6 and 2.42 through 2.42.3, and in 2.42.4 when the legacy `mount(2)` path is used without `/proc`, restricted non-root `mount` requests validate an `/etc/fstab` target before the mount operation re-resolves that pathname. A local low-privileged user authorized by an fstab `user` or `users` entry whose target has an attacker-writable ancestor can use `renameat2(RENAME_EXCHANGE)` to swap a path component and redirect an authorized mount to a root-owned location, such as mounting attacker-controlled content over `/etc/sudoers.d`, and thereby gain root privileges. Versions 2.41.5 and 2.42.2 pin targets for the new mount API, and 2.42.4 pins legacy targets through `/proc/self/fd`; the documented legacy fallback without `/proc` remains affected.","publishedAt":"2026-10-14T14:52:56.063Z","updatedAt":"2026-10-15T15:08:26.914Z","severity":{"score":7,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["util-linux util-linux"],"affected":[{"vendor":"util-linux","product":"util-linux","versions":[{"version":">= 2.17, <= 2.41.6","status":"affected"},{"version":">= 2.42, <= 2.42.4","status":"affected"}]}],"references":["https://github.com/util-linux/util-linux/security/advisories/GHSA-8gj5-72r3-428g","https://github.com/util-linux/util-linux/commit/0b010025a0e429bc80355c94db86a843395d49e2","https://github.com/util-linux/util-linux/commit/0d3d55975aa3492c62fd345eac38f41cd166c0b0","https://github.com/util-linux/util-linux/commit/2c773f336134acf016e639abb6f12ba7341fe4b8","https://github.com/util-linux/util-linux/commit/39fef62bf3226abb6bb018fa8750afa0327e84b4","https://github.com/util-linux/util-linux/commit/472cc3fb2d4d47cca7aab2e0b59eb3fb8a9359ec","https://github.com/util-linux/util-linux/commit/646fb66603d10a7ac337e14f566f1af48e3107c9","https://github.com/util-linux/util-linux/commit/708d1b3c51932dc5ba8082c7368187715e6a8d78","https://github.com/util-linux/util-linux/commit/78a860982e036f38fe9c0b3344998df5ac2c2ff5","https://github.com/util-linux/util-linux/commit/85d16b341f7232c9dbb4884b632e1e956584bee9","https://github.com/util-linux/util-linux/commit/a9508d216eb8977979102782672e0470cc9bf2a2","https://github.com/util-linux/util-linux/releases/tag/v2.41.5","https://github.com/util-linux/util-linux/releases/tag/v2.42.2","https://github.com/util-linux/util-linux/releases/tag/v2.42.4"],"weaknesses":["CWE-367"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53613.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53613","state":"PUBLISHED","datePublished":"2026-10-14T14:52:56.063Z","dateUpdated":"2026-10-15T15:08:26.914Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-09T19:39:52.405Z"},"containers":{"cna":{"title":"util-linux mount target TOCTOU allows local privilege escalation","descriptions":[{"lang":"en","value":"util-linux is a random collection of Linux utilities. In util-linux 2.17 through 2.41.6 and 2.42 through 2.42.3, and in 2.42.4 when the legacy `mount(2)` path is used without `/proc`, restricted non-root `mount` requests validate an `/etc/fstab` target before the mount operation re-resolves that pathname. A local low-privileged user authorized by an fstab `user` or `users` entry whose target has an attacker-writable ancestor can use `renameat2(RENAME_EXCHANGE)` to swap a path component and redirect an authorized mount to a root-owned location, such as mounting attacker-controlled content over `/etc/sudoers.d`, and thereby gain root privileges. Versions 2.41.5 and 2.42.2 pin targets for the new mount API, and 2.42.4 pins legacy targets through `/proc/self/fd`; the documented legacy fallback without `/proc` remains affected."}],"affected":[{"vendor":"util-linux","product":"util-linux","versions":[{"version":">= 2.17, <= 2.41.6","status":"affected"},{"version":">= 2.42, <= 2.42.4","status":"affected"}]}],"references":[{"url":"https://github.com/util-linux/util-linux/security/advisories/GHSA-8gj5-72r3-428g","name":"https://github.com/util-linux/util-linux/security/advisories/GHSA-8gj5-72r3-428g","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/util-linux/util-linux/commit/0b010025a0e429bc80355c94db86a843395d49e2","name":"https://github.com/util-linux/util-linux/commit/0b010025a0e429bc80355c94db86a843395d49e2","tags":["x_refsource_MISC"]},{"url":"https://github.com/util-linux/util-linux/commit/0d3d55975aa3492c62fd345eac38f41cd166c0b0","name":"https://github.com/util-linux/util-linux/commit/0d3d55975aa3492c62fd345eac38f41cd166c0b0","tags":["x_refsource_MISC"]},{"url":"https://github.com/util-linux/util-linux/commit/2c773f336134acf016e639abb6f12ba7341fe4b8","name":"https://github.com/util-linux/util-linux/commit/2c773f336134acf016e639abb6f12ba7341fe4b8","tags":["x_refsource_MISC"]},{"url":"https://github.com/util-linux/util-linux/commit/39fef62bf3226abb6bb018fa8750afa0327e84b4","name":"https://github.com/util-linux/util-linux/commit/39fef62bf3226abb6bb018fa8750afa0327e84b4","tags":["x_refsource_MISC"]},{"url":"https://github.com/util-linux/util-linux/commit/472cc3fb2d4d47cca7aab2e0b59eb3fb8a9359ec","name":"https://github.com/util-linux/util-linux/commit/472cc3fb2d4d47cca7aab2e0b59eb3fb8a9359ec","tags":["x_refsource_MISC"]},{"url":"https://github.com/util-linux/util-linux/commit/646fb66603d10a7ac337e14f566f1af48e3107c9","name":"https://github.com/util-linux/util-linux/commit/646fb66603d10a7ac337e14f566f1af48e3107c9","tags":["x_refsource_MISC"]},{"url":"https://github.com/util-linux/util-linux/commit/708d1b3c51932dc5ba8082c7368187715e6a8d78","name":"https://github.com/util-linux/util-linux/commit/708d1b3c51932dc5ba8082c7368187715e6a8d78","tags":["x_refsource_MISC"]},{"url":"https://github.com/util-linux/util-linux/commit/78a860982e036f38fe9c0b3344998df5ac2c2ff5","name":"https://github.com/util-linux/util-linux/commit/78a860982e036f38fe9c0b3344998df5ac2c2ff5","tags":["x_refsource_MISC"]},{"url":"https://github.com/util-linux/util-linux/commit/85d16b341f7232c9dbb4884b632e1e956584bee9","name":"https://github.com/util-linux/util-linux/commit/85d16b341f7232c9dbb4884b632e1e956584bee9","tags":["x_refsource_MISC"]},{"url":"https://github.com/util-linux/util-linux/commit/a9508d216eb8977979102782672e0470cc9bf2a2","name":"https://github.com/util-linux/util-linux/commit/a9508d216eb8977979102782672e0470cc9bf2a2","tags":["x_refsource_MISC"]},{"url":"https://github.com/util-linux/util-linux/releases/tag/v2.41.5","name":"https://github.com/util-linux/util-linux/releases/tag/v2.41.5","tags":["x_refsource_MISC"]},{"url":"https://github.com/util-linux/util-linux/releases/tag/v2.42.2","name":"https://github.com/util-linux/util-linux/releases/tag/v2.42.2","tags":["x_refsource_MISC"]},{"url":"https://github.com/util-linux/util-linux/releases/tag/v2.42.4","name":"https://github.com/util-linux/util-linux/releases/tag/v2.42.4","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":7,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-367","lang":"en","description":"CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-14T14:52:56.063Z"},"source":{"advisory":"GHSA-8gj5-72r3-428g","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-15T13:11:45.430649Z","id":"CVE-2026-53613","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T15:08:26.914Z"}}]}}}