Input validation error in FreeBSD - CVE-2026-101311
Published: October 14, 2026
Vulnerability details
The vulnerability allows a local user to crash the bhyve process or potentially execute arbitrary code in the host userspace context running the virtual machine.
The vulnerability exists due to improper validation of framebuffer dimensions, inconsistent maximum resolution constants, and unsynchronized framebuffer access in the bhyve framebuffer and RFB modules when handling framebuffer BAR writes and rendering framebuffer content. A local user can write arbitrary width and height values to the framebuffer BAR from a guest to crash the bhyve process or potentially execute arbitrary code in the host userspace context running the virtual machine.
Exploitation requires the framebuffer device to be exposed to the guest. Host-side execution remains subject to bhyve's Capsicum sandbox.