A denial of service vulnerability exists when Microsoft Hyper-V on a host server fails to properly validate specific malicious data from a user on a guest operating system. To exploit the vulnerability, an attacker who already has a privileged account on a guest operating system, running as a virtual machine, could run a specially crafted application. The security update addresses the vulnerability by resolving the conditions where Hyper-V would fail to handle these requests.
Nicolas Economou from <a href="https://www.bluefrostsecurity.de/en/">Blue Frost Security</a>