# CVE-2026-89931: KVM: nVMX: Ensure KVM_REQ_GET_NESTED_STATE_PAGES is cleared on VM-Exit

> A flaw in Linux KVM nested virtualization allows a local attacker to cause a denial of service by triggering double-mapping of VMCS pages.

- **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:** 16 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-89931, DEBIAN-CVE-2026-89931, GHSA-9jg7-wvq2-32v3, UBUNTU-CVE-2026-89931

## What is CVE-2026-89931?

CVE-2026-89931 is a 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: nVMX: Ensure KVM_REQ_GET_NESTED_STATE_PAGES is cleared on VM-Exit

Always check and clear KVM_REQ_GET_NESTED_STATE_PAGES when emulating a
nested VM-Exit to ensure the request is cleared, even when KVM was built
with CONFIG_KVM_HYPERV=n, as KVM subtly relies on the "check" to clear
the flag and thus avoid double-mapping the vmcs12 pages, e.g. if KVM
manages to bail from VM-Enter without processing the request, and then
emulates VMLAUNCH or VMRESUME.

## Which versions are affected by CVE-2026-89931?


## How do I fix CVE-2026-89931?

Apply the vendor's patch.

## Is CVE-2026-89931 being exploited?

There is no known exploitation of CVE-2026-89931 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89931 and fix it if it is affected.

What it is: CVE-2026-89931 is a 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-2026-89931 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-2026-89931/ (Markdown: https://insights.sbomify.com/CVE-2026-89931/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89931
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89931
- OSV: https://osv.dev/vulnerability/CVE-2026-89931

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89931/
Summaries are generated and may contain mistakes; the official description above is the record.