A remote code execution vulnerability exists when Windows Hyper-V on a host server fails to properly validate input from an authenticated user on a guest operating system, aka 'Windows Hyper-V Remote Code Execution Vulnerability'.
https://www.tenable.com/blog/tenable-roundup-for-microsoft-s-august-2019-patch-tuesday-dejablue
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0965