A remote code execution vulnerability exists in Microsoft Office when the software fails to properly handle objects in memory, aka "Office Remote Code Execution Vulnerability". This CVE ID is unique from CVE-2017-8510, CVE-2017-8511, CVE-2017-8512, CVE-2017-0260, and CVE-2017-8506.
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-8509