Microsoft Office 2016 Click-to-Run (C2R) and Microsoft Office 2016 for Mac allow an attacker to use a specially crafted file to perform actions in the security context of the current user, due to how Microsoft Office handles files in memory, aka "Microsoft Office Remote Code Execution Vulnerability".
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-11825