# CVE-2026-80555: s390/vfio_ccw: Free all memory if cp_init() fails

> A memory leak in the s390 vfio_ccw driver allows attackers to cause denial of service by triggering initialization failures.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 Aug 2026
- **Updated:** 27 Aug 2026
- **Also known as:** AZL-97758, BELL-CVE-2026-80555, DEBIAN-CVE-2026-80555, GHSA-w6fw-g579-ffcw, UBUNTU-CVE-2026-80555

## What is CVE-2026-80555?

CVE-2026-80555 is a high-severity memory corruption 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: Free all memory if cp_init() fails

The routine cp_free() is called to unpin/free any memory once an I/O
is completed successfully, or if cp_prefetch() fails. But if cp_init()
fails, and cp->initialized is not enabled, the same routine cannot be
used to free all the memory.

An attempt to address this exists in ccwchain_handle_ccw(), where a
single call to ccwchain_free() is made for the currently-processed
CCW segment. But this will leak other segments (created as a result
of a Transfer in Channel) that had been allocated as part of the same
channel program.

Address this by performing the cleanup outside of the recursive
ccwchain_handle_ccw()/ccwchain_loop_tic() logic.

## Which versions are affected by CVE-2026-80555?


## How do I fix CVE-2026-80555?

Apply the vendor's patch.

## Is CVE-2026-80555 being exploited?

There is no known exploitation of CVE-2026-80555 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80555 and fix it if it is affected.

What it is: CVE-2026-80555 is a high-severity memory corruption 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-2026-80555 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-2026-80555/ (Markdown: https://insights.sbomify.com/CVE-2026-80555/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80555
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80555
- OSV: https://osv.dev/vulnerability/CVE-2026-80555

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80555/
Summaries are generated and may contain mistakes; the official description above is the record.