WebKit, as used in Apple iOS before 9.3.2, Safari before 9.1.1, and tvOS before 9.2.1, improperly tracks taint attributes, which allows remote attackers to obtain sensitive information via a crafted web site.
https://support.apple.com/HT206568
https://support.apple.com/HT206565
https://support.apple.com/HT206564
http://www.securitytracker.com/id/1035888
http://www.securityfocus.com/archive/1/538522/100/0/threaded
http://lists.apple.com/archives/security-announce/2016/May/msg00005.html
http://lists.apple.com/archives/security-announce/2016/May/msg00002.html
http://lists.apple.com/archives/security-announce/2016/May/msg00001.html