CVE-2026-101309

7.0 HIGH 0.1% exploit odds No fix listed Code execution OS & kernel

What it is

The xHCI (USB 3) device model did not validate or save the event ring size provided by the guest. The size was re-read from guest memory on each use, and Transfer Request Block (TRB) fields were loaded without protection against concurrent modification by the guest. This race condition could be triggered by a guest running malicious, privileged code. A malicious guest can crash the bhyve process or potentially execute arbitrary code in the host userspace context running the virtual machine, subject to bhyve's Capsicum sandbox.

At a glance

Exploitability: Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
Exploit odds: 0.1% chance of exploitation in the next 30 days (EPSS).
Fix: No patch or advisory is linked yet. Look at mitigations or restrict exposure.