A remote code execution vulnerability exists in the Windows Remote Desktop Client when a user connects to a malicious server, aka 'Remote Desktop Client Remote Code Execution Vulnerability'. This CVE ID is unique from CVE-2019-0787, CVE-2019-0788, CVE-2019-1290.
https://www.tenable.com/blog/microsofts-september-2019-patch-tuesday-tenable-roundup
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1291