# CVE-2026-64286: KVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU

> A missing pointer clearance in KVM arm64 allows a malicious host to trigger a null dereference at EL2, potentially leading to privilege escalation or code execution.

- **Severity:** High 8.2 (`CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Jul 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-93695, BELL-CVE-2026-64286, DEBIAN-CVE-2026-64286, GHSA-5rwh-cw23-rrm6, ROOT-OS-DEBIAN-13-CVE-2026-64286, ROOT-OS-UBUNTU-2204-CVE-2026-64286, UBUNTU-CVE-2026-64286

## What is CVE-2026-64286?

CVE-2026-64286 is a high-severity vulnerability in Linux kernel, published on 25 Jul 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: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU

flush_hyp_vcpu() copies the host vCPU context into the hyp's private
vCPU on every run. ctxt_to_vcpu() expects a guest context to have a
NULL __hyp_running_vcpu, which is only ever set on the host context, so
that it resolves the vCPU via container_of(). While this is generally
the case, flush_hyp_vcpu() copies the context verbatim and does not
enforce this, so a value provided by the host is dereferenced at EL2
(host -> EL2).

Fix by clearing __hyp_running_vcpu after the copy.

Weakness: CWE-822 (Untrusted Pointer Dereference)

## Which versions are affected by CVE-2026-64286?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64286?

Apply the vendor's patch.

## Is CVE-2026-64286 being exploited?

There is no known exploitation of CVE-2026-64286 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-64286 and fix it if it is affected.

What it is: CVE-2026-64286 is a high-severity vulnerability in Linux kernel, published on 25 Jul 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-2026-64286 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-64286/ (Markdown: https://insights.sbomify.com/CVE-2026-64286/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64286
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64286
- OSV: https://osv.dev/vulnerability/CVE-2026-64286

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64286/
Summaries are generated and may contain mistakes; the official description above is the record.