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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| util-linux | util-linux | 2.39 – < 2.41.6, 2.42 – < 2.42.3 | 2.41.6 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | util-linux | 2.42.3-1 | — |
| Debian 13 | util-linux | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | util-linux | No fix yet | — |
| Ubuntu 26.04 LTS | util-linux | No fix yet | — |
| Ubuntu 24.04 LTS | util-linux | No fix yet | — |
| Ubuntu 18.04 LTS | util-linux | No fix yet | — |
| Ubuntu 14.04 LTS | util-linux | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | util-linux | No fix yet | — |
| Ubuntu Pro 16.04 LTS | util-linux | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | uuidd +17 | 2.42.2-3.4.hum1 | RHSA-2026:63162 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | uuidd +13 | 2.40.2-18.el10_2.20 | ALSA-2026:93461 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | util-linux | 2.40.2-18.el10_2.20 | RLSA-2026:93461 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | util-linux +2 | 2.41.1-160000.5.1 | SUSE-SU-2026:23870-1, SUSE-SU-2026:23861-1 |
| SLES 16.0 | util-linux +2 | 2.41.1-160000.5.1 | SUSE-SU-2026:23870-1, SUSE-SU-2026:23861-1 |
| SLE Micro 6.2 | util-linux +1 | 2.41.1-160000.5.1 | SUSE-SU-2026:23884-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | util-linux | 2.42.3-1.1 | openSUSE-SU-2026:11870-1 |
| openSUSE Leap 16.0 | util-linux +2 | 2.41.1-160000.5.1 | openSUSE-SU-2026:21905-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | util-linux | 2.42.3-r0 | — |
| Alpine v3.23 | util-linux | 2.41.6-r0 | — |
| Alpine v3.22 | util-linux | 2.41.6-r0 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | util-linux | 2.40.2-6 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | uuidd +13 | 2.40.2-18.0.1.el10_2.20 | ELSA-2026-93461 |
Advisories 10
- WID-SEC-2026-3180 util-linux: Schwachstelle ermöglicht Privilegieneskalation BSI CERT-Bund (WID) · Nov 4, 2026
- RLSA-2026:93461 Important: util-linux security update Rocky Linux Security Advisories · Nov 3, 2026
- ALSA-2026:93461 Important: util-linux security update AlmaLinux Security Advisories · Nov 2, 2026
- ELSA-2026-93461 Important: util-linux security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Nov 2, 2026
- RHSA-2026:63162 Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- SUSE-SU-2026:23884-1 Security update for util-linux SUSE / openSUSE Security Updates · Sep 30, 2026
- SUSE-SU-2026:23870-1 Security update for util-linux SUSE / openSUSE Security Updates · Sep 27, 2026
- SUSE-SU-2026:23861-1 Security update for util-linux SUSE / openSUSE Security Updates · Sep 27, 2026
- openSUSE-SU-2026:21905-1 Security update for util-linux SUSE / openSUSE Security Updates · Sep 25, 2026
- openSUSE-SU-2026:11870-1 libblkid-devel-2.42.3-1.1 on GA media SUSE / openSUSE Security Updates · Sep 24, 2026
References
- GitHub Security Advisory (GHSA-m25x-3hj9-m26f) vendor-advisory
- Patch Commit patch
- Patch Commit patch
- Patch Commit patch
- https://github.com/util-linux/util-linux/blob/v2.42.2/libmount/src/context_mount.c#L476 technical-description
- https://github.com/util-linux/util-linux/blob/v2.42.2/libmount/src/context_mount.c#L892 technical-description
- https://github.com/util-linux/util-linux product
- VulnCheck Advisory: util-linux libmount Privilege Escalation via Failed Mount Helper third-party-advisory