Description
A flaw was found in util-linux. Restricted bind mounts take the source path from fstab but do not pin that source before the privileged mount. A local unprivileged user who can replace the authorized source or a writable ancestor can redirect SUID mount(8) to bind another host directory. If the fstab entry also sets X-mount.owner, X-mount.group, or X-mount.mode, root then changes ownership or mode on that redirected inode.
References6
- access.redhat.com/errata/RHSA-2026:63162
- access.redhat.com/errata/RHSA-2026:93461
- access.redhat.com/security/cve/CVE-2026-78410
- bugzilla.redhat.com/show_bug.cgi?id=2522684
- github.com/util-linux/util-linux/security/advisories/GHSA-rh77-…
- github.com/util-linux/util-linux/security/advisories/GHSA-rh77-…
Metrics
- CVSS 3.1
-
7.8
HIGH
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 5 · as of 2 November 2026
- CWE
- CWE-367
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