Util-linux: util-linux: restricted bind mounts do not pin the source, allowing x-mount.owner/group/mode redirection
CVE-2026-78410 · published 2 Sept 2026
How serious is it
- Severity: high, CVSS score 7.8 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-78410?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Red Hat Red Hat Hardened Images
- Red Hat Red Hat Enterprise Linux 10
- Red Hat Red Hat Enterprise Linux 7
- Red Hat Red Hat Enterprise Linux 8
- Red Hat Red Hat Enterprise Linux 9
- Red Hat Red Hat Enterprise Linux 9
- Red Hat Red Hat Enterprise Linux 9
- Red Hat Red Hat OpenShift Container Platform 4
- Red Hat Red Hat OpenShift Container Platform 4
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
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.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- access.redhat.com/errata/RHSA-2026:63162
- 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-rh77-686x-2f2m
Merged from CVE List. Last updated 29 Oct 2026. All vulnerabilities · RSS · JSON