PatchTheCVECVE-2026-101309: The xHCI (USB 3) device model did not validate or save the event ring size provided by the guest
CVE-2026-101309 is a high-severity flaw (CVSS 7.0) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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 hos
Why this priority
- High severity
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 7.0 (High) |
| Attack vector | Local |
| Attack complexity | High |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.1% (top 98%) |
| CISA exploited list | No |
| Weakness | CWE-362 |
| Published | 2026-10-15 |
| Last modified | 2026-10-16 |
Last updated 2026-10-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-101309?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-101309 being exploited?
CVE-2026-101309 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-101309 affect?
CVE-2026-101309 affects affected software. Severity is high (CVSS 7.0). 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
How urgent is CVE-2026-101309?
Priority 25/100. High severity