CVE 2016-3366

Microsoft Outlook 2007 SP3, Outlook 2010 SP2, Outlook 2013 SP1, Outlook 2013 RT SP1, Outlook 2016, and Outlook 2016 for Mac do not properly implement RFC 2046, which allows remote attackers to bypass virus or spam detection via crafted MIME data in an e-mail attachment, aka "Microsoft Office Spoofing Vulnerability."

See the CVE page on Mitre.org for more details.