Vulnerability · Published Oct 15, 2026 · Assigned by freebsd

CVE-2026-101309Multiple vulnerabilities in bhyve device models

High 7.0

In plain English

A high-severity race condition in FreeBSD from FreeBSD. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities).

Severity (CVSS 3.1)7.0High
Exploit odds (30 days)0.1%top 98.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

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.

Affected products (as reported)

VendorProductVersions
FreeBSD FreeBSD 15.1-RELEASE – before p514.5-RELEASE – before p214.4-RELEASE – before p11

Weakness: CWE-362 · Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

References