CVE-2026-76642
highutil-linux versions through 2.41.5 and 2.42.2 fail to check mount helper exit status before running post-mount hooks, allowing unprivileged users to execute pr…
util-linux versions through 2.41.5 and 2.42.2 fail to check mount helper exit status before running post-mount hooks, allowing unprivileged users to execute privileged operations on pre-existing filesystems. Attackers can exploit X-mount.idmap or X-mount.owner hooks to clone filesystems with inherited suid bits or modify target inode permissions after a helper fails, achieving privilege escalation.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/util-linux/util-linux disclosure@vulncheck.com
- https://github.com/util-linux/util-linux/blob/v2.42.2/libmount/src/context_mount.c#L476 disclosure@vulncheck.com
- https://github.com/util-linux/util-linux/blob/v2.42.2/libmount/src/context_mount.c#L892 disclosure@vulncheck.com
- https://github.com/util-linux/util-linux/commit/1d14676ea70003e9f5b2a6a76af0cadb1190411a disclosure@vulncheck.com
- https://github.com/util-linux/util-linux/commit/a15c00a9e545aa8b9cf6ec0f888ff6c7b3eaeedc disclosure@vulncheck.com
- https://github.com/util-linux/util-linux/commit/f57cea130839c0af8dc0525274267ae4cfd66bbf disclosure@vulncheck.com
- https://github.com/util-linux/util-linux/security/advisories/GHSA-m25x-3hj9-m26f disclosure@vulncheck.com
- https://www.vulncheck.com/advisories/util-linux-libmount-privilege-escalation-via-failed-m... disclosure@vulncheck.com
- https://github.com/util-linux/util-linux/security/advisories/GHSA-m25x-3hj9-m26f 134c704f-9b21-4f2e-91b3-4a467353bcc0