# CVE-2026-53613: util-linux mount target TOCTOU allows local privilege escalation

> Local attackers can exploit a race condition in util-linux mount to escalate privileges to root by redirecting authorized mounts to sensitive system paths.

- **Severity:** High 7.0 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 14 Oct 2026
- **Updated:** 15 Oct 2026
- **Also known as:** ALPINE-CVE-2026-53613, AZL-108555, BELL-CVE-2026-53613, DEBIAN-CVE-2026-53613, ECHO-c24c-41a0-9a74, GHSA-8gj5-72r3-428g, ROOT-OS-DEBIAN-11-CVE-2026-53613, UBUNTU-CVE-2026-53613

## What is CVE-2026-53613?

CVE-2026-53613 is a high-severity vulnerability in util-linux, published on 14 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

util-linux is a random collection of Linux utilities. In util-linux 2.17 through 2.41.6 and 2.42 through 2.42.3, and in 2.42.4 when the legacy `mount(2)` path is used without `/proc`, restricted non-root `mount` requests validate an `/etc/fstab` target before the mount operation re-resolves that pathname. A local low-privileged user authorized by an fstab `user` or `users` entry whose target has an attacker-writable ancestor can use `renameat2(RENAME_EXCHANGE)` to swap a path component and redirect an authorized mount to a root-owned location, such as mounting attacker-controlled content over `/etc/sudoers.d`, and thereby gain root privileges. Versions 2.41.5 and 2.42.2 pin targets for the new mount API, and 2.42.4 pins legacy targets through `/proc/self/fd`; the documented legacy fallback without `/proc` remains affected.

Weakness: CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition)

## Which versions are affected by CVE-2026-53613?


## How do I fix CVE-2026-53613?

Upgrade to a fixed version.

## Is CVE-2026-53613 being exploited?

There is no known exploitation of CVE-2026-53613 in the wild and no public exploit code.

Public exploit code:

- https://github.com/mohamedjawady/CVE-2026-53613-poc (github_poc): https://github.com/mohamedjawady/CVE-2026-53613-poc

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53613 and fix it if it is affected.

What it is: CVE-2026-53613 is a high-severity vulnerability in util-linux, published on 14 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-53613 in the wild and no public exploit code.

Affected product: util-linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-53613/ (Markdown: https://insights.sbomify.com/CVE-2026-53613/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53613
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53613
- OSV: https://osv.dev/vulnerability/CVE-2026-53613

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53613/
Summaries are generated and may contain mistakes; the official description above is the record.