# CVE-2026-80684: KVM: s390: pci: Fix NULL dereference on AIBV allocation failure

> A missing NULL check in the Linux kernel's KVM s390 PCI code allows a local attacker to cause a denial of service via a NULL pointer dereference.

- **Severity:** Critical 9.3 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/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:** 28 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** AZL-98057, BELL-CVE-2026-80684, DEBIAN-CVE-2026-80684, GHSA-q4fh-xh4r-x3xp, UBUNTU-CVE-2026-80684

## What is CVE-2026-80684?

CVE-2026-80684 is a critical vulnerability in Linux, published on 28 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:

KVM: s390: pci: Fix NULL dereference on AIBV allocation failure

The airq_iv_create() can return NULL on failure, but the return value was
never checked. If it fails, zdev->aibv will be NULL and fail when
dereferenced in kvm_zpci_set_airq(). Add a NULL check and free the
previously allocated AISB bit and zdev->aisb on failure.

## Which versions are affected by CVE-2026-80684?


## How do I fix CVE-2026-80684?

Apply the vendor's patch.

## Is CVE-2026-80684 being exploited?

There is no known exploitation of CVE-2026-80684 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80684 and fix it if it is affected.

What it is: CVE-2026-80684 is a critical vulnerability in Linux, published on 28 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-2026-80684 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-2026-80684/ (Markdown: https://insights.sbomify.com/CVE-2026-80684/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80684
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80684
- OSV: https://osv.dev/vulnerability/CVE-2026-80684

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80684/
Summaries are generated and may contain mistakes; the official description above is the record.