# CVE-2026-89727: KVM: arm64: GICv2: Don't WARN on out-of-range GICV_DIR INTID

> A malicious guest can trigger a kernel panic on the host by writing an invalid interrupt ID, causing denial of service if panic_on_warn is enabled.

- **Severity:** Not scored
- **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:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-89727, GHSA-v32g-7j7h-69wx, UBUNTU-CVE-2026-89727

## What is CVE-2026-89727?

CVE-2026-89727 is a denial of service vulnerability in Linux, published on 11 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: GICv2: Don't WARN on out-of-range GICV_DIR INTID

vgic_v2_deactivate() passes the INTID a guest wrote to GICV_DIR straight
to vgic_get_vcpu_irq(), and treats a failed lookup as a "can't happen"
condition with WARN_ON_ONCE().

The guest can make it happen at will, though: for any INTID outside of
the implemented SGI, PPI and SPI ranges the lookup returns NULL, since
GICv2 has no LPIs. A guest running with EOImode==1 writing such an INTID
to GICV_DIR triggers the WARN, and panics hosts running with
panic_on_warn.

Drop the WARN and ignore failed lookups.

## Which versions are affected by CVE-2026-89727?


## How do I fix CVE-2026-89727?

Apply the vendor's patch.

## Is CVE-2026-89727 being exploited?

There is no known exploitation of CVE-2026-89727 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89727 and fix it if it is affected.

What it is: CVE-2026-89727 is a denial of service vulnerability in Linux, published on 11 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-2026-89727 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-2026-89727/ (Markdown: https://insights.sbomify.com/CVE-2026-89727/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89727
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89727
- OSV: https://osv.dev/vulnerability/CVE-2026-89727

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89727/
Summaries are generated and may contain mistakes; the official description above is the record.