The kernel in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT Gold and 8.1, and Windows 10 mishandles junctions during mountpoint creation, which makes it easier for local users to gain privileges by leveraging certain sandbox access, aka "Windows Mount Point Elevation of Privilege Vulnerability."
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2015/ms15-111