# CVE-2026-80552: s390/vfio_ccw: Ensure index for read/write regions are within range

> A missing bounds check in the s390 vfio_ccw driver allows out-of-bounds access, potentially causing a kernel crash or denial of service.

- **Severity:** High 8.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/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:** 26 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** AZL-97827, BELL-CVE-2026-80552, DEBIAN-CVE-2026-80552, GHSA-fp69-7jh5-pp7r, UBUNTU-CVE-2026-80552

## What is CVE-2026-80552?

CVE-2026-80552 is a high-severity vulnerability in Linux, published on 26 Aug 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:

s390/vfio_ccw: Ensure index for read/write regions are within range

The introduction of the capability chain rightly clamped the
region indexes to the range of the capabilities itself, but
neglected to do so for the existing read/write regions which
should also be enforced.

## Which versions are affected by CVE-2026-80552?


## How do I fix CVE-2026-80552?

Apply the vendor's patch.

## Is CVE-2026-80552 being exploited?

There is no known exploitation of CVE-2026-80552 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80552 and fix it if it is affected.

What it is: CVE-2026-80552 is a high-severity vulnerability in Linux, published on 26 Aug 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-2026-80552 in the wild and no public exploit code.

Affected product: 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-2026-80552/ (Markdown: https://insights.sbomify.com/CVE-2026-80552/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80552
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80552
- OSV: https://osv.dev/vulnerability/CVE-2026-80552

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80552/
Summaries are generated and may contain mistakes; the official description above is the record.