CVE-2026-101309
Received
Received - Intake
Race Condition in bhyve xHCI Device Model
Vulnerability report for CVE-2026-101309, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-15
Last updated on: 2026-10-15
Assigner: FreeBSD
Description
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.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| FreeBSD | FreeBSD | 15.1-RELEASE |
| FreeBSD | FreeBSD | 14.5-RELEASE |
| FreeBSD | FreeBSD | 14.4-RELEASE |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-362 | The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently. |
