CVE-2026-101309
The xHCI (USB 3) device model did not validate or save the event ring size provided by the guest
- Risk score
- 42/100
- CVSS
- 7.0 v3.1
- Exploit chance (30 days)
- 0.1%
- Published
- 15 Oct 2026
Open in the live forecast Today's forecast
What to know
- 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 ru…
- Affected
- See advisory
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Why it is Yellow
- CVSS 7.0 high
References
Original 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.
Last activity 15 Oct 2026. Patch Forecast updates every hour.