CVE-2026-101309
UnknownSummary
In bhyve's xHCI (USB 3) device model, the event ring size provided by the guest was not validated or saved. 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.
Risk Assessment
A malicious guest can crash the bhyve process or potentially execute arbitrary code in the host userspace context, subject to bhyve's Capsicum sandbox. Affects bhyve virtualization environments.
Recommendation
Update bhyve to a version containing fixes for event ring size validation and protection of TRB fields against concurrent modification. Keep the Capsicum sandbox enabled.
Other vulnerabilities in bhyve
See all- CVE-2026-101311Unknown
In bhyve's framebuffer device model, maximum resolution constants were duplicated between the framebuffer and RFB modules and got out of sync. Additionally, writes to the framebuffer BAR could set arbitrary width and height values without validation, and the framebuffer BAR I/O and RFB rendering threads were not synchronized.
- CVE-2026-101310Unknown
In bhyve's HDA audio device model, zero-length Buffer Descriptor List (BDL) entries were not checked when starting a stream. A zero-length entry caused an out-of-bounds read or write during DMA transfer processing. BDL fields could also be modified by the guest after validation.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS