CVE-2026-76642
Description
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Mixed 4 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Affected | — |
| sid | Fixed | 2.42.3-1 |
| forky | Affected | — |
| bookworm | Affected | — |
References
- https://security-tracker.debian.org/tracker/CVE-2026-76642
- https://github.com/util-linux/util-linux/security/advisories/GHSA-m25x-3hj9-m26f
- https://github.com/util-linux/util-linux/commit/f57cea130839c0af8dc0525274267ae4cfd66bbf
- https://github.com/util-linux/util-linux/commit/1d14676ea70003e9f5b2a6a76af0cadb1190411a
- https://github.com/util-linux/util-linux/commit/a15c00a9e545aa8b9cf6ec0f888ff6c7b3eaeedc
- https://github.com/util-linux/util-linux/blob/v2.42.2/libmount/src/context_mount.c#L476
- https://github.com/util-linux/util-linux/blob/v2.42.2/libmount/src/context_mount.c#L892
- https://github.com/util-linux/util-linux
- https://www.vulncheck.com/advisories/util-linux-libmount-privilege-escalation-via-failed-mount-helper
- https://www.suse.com/security/cve/CVE-2026-76642.html
CWEs
CWE-390
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.