# CVE-2026-98927: KVM: arm64: nv: Fix life cycle of the nested_mmus array


- **Severity:** High 7.0 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 23 Oct 2026
- **Updated:** 24 Oct 2026
- **Also known as:** BELL-CVE-2026-98927, DEBIAN-CVE-2026-98927, GHSA-2374-8v6x-x95c, UBUNTU-CVE-2026-98927

## What is CVE-2026-98927?

CVE-2026-98927 is a high-severity vulnerability in Linux, published on 23 Oct 2026. 

### Official description

In the Linux kernel, the following vulnerability has been resolved:

KVM: arm64: nv: Fix life cycle of the nested_mmus array

The nested_mmus array holds the shadow page tables that are used when
a guest is running a nested context. These structures are allocated on
VCPU_INIT for whole guest, which implies that they may have to be
relocated as the array grows.

Should a VCPU_INIT occur whilst a vcpu is actively running an L2 and
that the allocation requires relocation, that vcpu will still be
running with a pointer to the previous structure, which will have been
freed.

Fix this by turning the array of structures to an array of pointers,
which is now allocated at VM creation, sized to the absolute maximum
that KVM can handle.

In turn, each VCPU_INIT contributes S2_MMU_PER_VCPU to the pool. No
reallocation is ever performed, and the life cycle of each object is
much clearer:

- the nested_mmus array is allocated in kvm_init_nested(), and freed
  in kvm_arch_destroy_vm()

- s2_mmu structures are allocated in kvm_vcpu_init_nested(), and freed
  on kvm_arch_flush_shadow_all()

Finally, the freeing of vcpu->arch.vncr_array is made consistent
rather than being done on some failure paths, but not others.

## Which versions are affected by CVE-2026-98927?


## How do I fix CVE-2026-98927?

Upgrade to a fixed version.

## Is CVE-2026-98927 being exploited?

There is no known exploitation of CVE-2026-98927 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98927 and fix it if it is affected.

What it is: CVE-2026-98927 is a high-severity vulnerability in Linux, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-98927 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-2026-98927/ (Markdown: https://insights.sbomify.com/CVE-2026-98927/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98927
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98927
- OSV: https://osv.dev/vulnerability/CVE-2026-98927

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98927/
Summaries are generated and may contain mistakes; the official description above is the record.