CVE-2026-101309 Multiple vulnerabilities in bhyve device models
A race condition in the bhyve xHCI device model allows a malicious guest to crash the host or execute arbitrary code in the host userspace context.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-101309?
CVE-2026-101309 is a high-severity vulnerability in FreeBSD, published on 15 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-362
Which versions are affected by CVE-2026-101309?
How do I fix CVE-2026-101309?
No fix has been published for CVE-2026-101309 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-101309 being exploited?
There is no known exploitation of CVE-2026-101309 in the wild and no public exploit code.
Sources
Also known as GHSA-6jf6-r4g2-3vh5.