An elevation of privilege vulnerability exists when Windows Hyper-V on a host server fails to properly handle objects in memory. An attacker who successfully exploited these vulnerabilities could gain elevated privileges on a target operating system.
This vulnerability by itself does not allow arbitrary code to be run. However, this vulnerability could be used in conjunction with one or more vulnerabilities (e.g. a remote code execution vulnerability and another elevation of privilege) that could take advantage of the elevated privileges when running.
The update addresses the vulnerabilities by correcting how Windows Hyper-V handles objects in memory.