# CVE-2026-89912: KVM: arm64: vgic-its: Don't dereference a NULL collection on ITT save

> A guest can trigger a host kernel crash via a specific sequence of ITS commands during migration, causing denial of service.

- **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:** 16 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-101547, BELL-CVE-2026-89912, DEBIAN-CVE-2026-89912, GHSA-6q94-4246-2272, UBUNTU-CVE-2026-89912

## What is CVE-2026-89912?

CVE-2026-89912 is a high-severity vulnerability in Linux, published on 16 Sep 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: arm64: vgic-its: Don't dereference a NULL collection on ITT save

MAPC with V=0 drops ite->collection but leaves the ITE on the device's
ITT list, and vgic_its_save_ite() dereferences it unconditionally. A
guest that issues MAPD, MAPTI and then MAPC(V=0) therefore oopses the
host when the VMM issues KVM_DEV_ARM_ITS_SAVE_TABLES to migrate it.
That sequence is UNPREDICTABLE per the architecture, but KVM already
handles the resulting state in the translate, MOVI and DISCARD paths.

Save a zeroed entry, which vgic_its_restore_ite() reads back as
invalid. Skipping the ITE instead would leave the ITT slot holding
whatever is in guest memory, and restore rejects an entry naming a
collection the restored collection table does not have.

## Which versions are affected by CVE-2026-89912?


## How do I fix CVE-2026-89912?

Apply the vendor's patch.

## Is CVE-2026-89912 being exploited?

There is no known exploitation of CVE-2026-89912 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89912 and fix it if it is affected.

What it is: CVE-2026-89912 is a high-severity vulnerability in Linux, published on 16 Sep 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-2026-89912 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-2026-89912/ (Markdown: https://insights.sbomify.com/CVE-2026-89912/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89912
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89912
- OSV: https://osv.dev/vulnerability/CVE-2026-89912

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89912/
Summaries are generated and may contain mistakes; the official description above is the record.