# CVE-2026-64475: vfio/pci: Release the VGA arbiter client on register_device() failure

> A use-after-free vulnerability in the Linux kernel's VFIO PCI driver allows attackers to potentially execute code or escalate privileges via a stale VGA arbiter callback.

- **Severity:** High 8.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **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:** 25 Jul 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-93909, BELL-CVE-2026-64475, DEBIAN-CVE-2026-64475, GHSA-mj56-4c42-9869, ROOT-OS-DEBIAN-12-CVE-2026-64475, ROOT-OS-UBUNTU-2204-CVE-2026-64475, UBUNTU-CVE-2026-64475

## What is CVE-2026-64475?

CVE-2026-64475 is a high-severity use after free vulnerability in Linux, 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:

vfio/pci: Release the VGA arbiter client on register_device() failure

The re-order in the Fixes commit below displaced vfio_pci_vga_init() as
the last failure point of what is now vfio_pci_core_register_device()
without introducing an unwind for the VGA arbiter registration.

In current kernels this is mostly benign because vfio_pci_set_decode()
only uses pci_dev state, but the original failure path could leave a
callback with a freed vdev cookie.  The stale registration also becomes
unsafe again once the callback follows drvdata to the vfio device.

Add the required VGA unwind callout.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-64475?


## How do I fix CVE-2026-64475?

Apply the vendor's patch.

## Is CVE-2026-64475 being exploited?

There is no known exploitation of CVE-2026-64475 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-64475 and fix it if it is affected.

What it is: CVE-2026-64475 is a high-severity use after free vulnerability in Linux, 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-2026-64475 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-2026-64475/ (Markdown: https://insights.sbomify.com/CVE-2026-64475/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64475
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64475
- OSV: https://osv.dev/vulnerability/CVE-2026-64475

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64475/
Summaries are generated and may contain mistakes; the official description above is the record.