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.
- 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
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
Which versions are affected by CVE-2026-64475?
How do I fix CVE-2026-64475?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-64475 being exploited?
There is no known exploitation of CVE-2026-64475 in the wild and no public exploit code.
Sources
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 and 1 more.