Microsoft Internet Explorer 9 through 11 and the Internet Messaging API in Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, and Windows 7 SP1 allow remote attackers to determine the existence of arbitrary files via a crafted web site, aka "Internet Explorer Information Disclosure Vulnerability."
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2016/ms16-126
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2016/ms16-118