WebKit in Apple iOS before 9 does not properly select the cases in which a Cascading Style Sheets (CSS) document is required to have the text/css content type, which allows remote attackers to bypass the Same Origin Policy via a crafted web site.
https://support.apple.com/HT205265
https://support.apple.com/HT205212
http://www.securitytracker.com/id/1033609
http://www.securityfocus.com/bid/76766
http://lists.apple.com/archives/security-announce/2015/Sep/msg00007.html
http://lists.apple.com/archives/security-announce/2015/Sep/msg00001.html