Linux Kernel Vulnerability in Hyper-V VMBus Connection Management

CVE-2026-99216

What is CVE-2026-99216?

A vulnerability exists in the Linux kernel relating to the management of VMBus connection states during exit processes. The issue arises when the code erroneously forces the disconnection state prior to a VMBus disconnect call, conflicting with the conditions required to properly unload the VMBus connection. As a result, the connection may persist, leading to potential security risks where the Hyper-V host continues sending unexpected messages or posting VMBus interrupts. This flaw was introduced in a previous commit and requires attention to ensure secure handling of VMBus connections.

References