Internet Explorer in Microsoft Windows 7 SP1, Windows Server 2008 R2 SP1, Windows 8.1 and Windows RT 8.1, Windows Server 2012 R2, and Microsoft Edge and Internet Explorer in Windows 10 Gold, 1511, 1607, 1703, and Windows Server 2016 allow an attacker to obtain specific information used in the parent domain, due to Microsoft browser parent domain verification in certain functionality, aka "Microsoft Browser Information Disclosure Vulnerability".
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-8736
http://www.securitytracker.com/id/1039343