The Hyper-V server implementation in Microsoft Windows Server 2008 Gold, SP2, and R2 on the x64 platform allows guest OS users to cause a denial of service (host OS hang) via a crafted application that executes a malformed series of machine instructions, aka "Hyper-V Instruction Set Validation Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A8006
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2010/ms10-010