An elevation of privilege exists in Windows COM Desktop Broker, aka "Windows COM Elevation of Privilege Vulnerability." This affects Windows Server 2012 R2, Windows RT 8.1, Windows Server 2019, Windows Server 2016, Windows 8.1, Windows 10, Windows 10 Servers.
https://www.exploit-db.com/exploits/46162/
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0552