Microsoft Excel 2007 SP3, Excel 2010 SP2, Excel 2013 SP1, Excel 2013 RT SP1, Excel 2016, Excel for Mac 2011, Excel 2016 for Mac, Office Compatibility Pack SP3, Excel Viewer, and Excel Services on SharePoint Server 2007 SP3, 2010 SP2, and 2013 SP1 allow remote attackers to execute arbitrary code via a crafted Office document, aka "Microsoft Office Memory Corruption Vulnerability."
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2015/ms15-116
http://www.zerodayinitiative.com/advisories/ZDI-15-543
http://www.securitytracker.com/id/1034122