# CVE-2026-53174: ovl: keep err zero after successful ovl_cache_get()

> A logic error in the Linux kernel overlayfs module can return a bogus error code, potentially causing denial of service during directory listing operations.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/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:** 25 Jun 2026
- **Updated:** 5 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-53174, GHSA-xxjh-4wcx-gmq5, UBUNTU-CVE-2026-53174

## What is CVE-2026-53174?

CVE-2026-53174 is a high-severity vulnerability in Linux kernel, published on 25 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

ovl: keep err zero after successful ovl_cache_get()

ovl_iterate_merged() stores PTR_ERR(cache) in err before checking
IS_ERR(cache). On success err holds the truncated cache pointer and
can be returned as a bogus non-zero error.

The syzbot reproducer reaches this through overlay-on-overlay readdir:

  getdents64
    iterate_dir(outer overlay file)
      ovl_iterate_merged()
        ovl_cache_get()
          ovl_dir_read_merged()
            ovl_dir_read()
              iterate_dir(inner overlay file)
                ovl_iterate_merged()

Only compute PTR_ERR(cache) on the error path.

## Which versions are affected by CVE-2026-53174?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53174?

Apply the vendor's patch.

## Is CVE-2026-53174 being exploited?

There is no known exploitation of CVE-2026-53174 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53174 and fix it if it is affected.

What it is: CVE-2026-53174 is a high-severity vulnerability in Linux kernel, published on 25 Jun 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-2026-53174 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-53174/ (Markdown: https://insights.sbomify.com/CVE-2026-53174/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53174
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53174
- OSV: https://osv.dev/vulnerability/CVE-2026-53174

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53174/
Summaries are generated and may contain mistakes; the official description above is the record.