Windows Hyper-V in Microsoft Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, 1607, 1703, and Windows Server 2016 allows an attacker to gain elevated privileges on a target guest operating system when Windows Hyper-V instruction emulation fails to properly enforce privilege levels, aka "Hypervisor Code Integrity Elevation of Privilege Vulnerability".