The private-browsing implementation in WebKit in Apple Safari before 6.2.5, 7.x before 7.1.5, and 8.x before 8.0.5 places browsing history into an index, which might allow local users to obtain sensitive information by reading index entries.
https://support.apple.com/HT204658
http://www.ubuntu.com/usn/USN-2937-1
http://www.securitytracker.com/id/1032047
http://lists.opensuse.org/opensuse-updates/2016-03/msg00132.html
http://lists.apple.com/archives/security-announce/2015/Apr/msg00000.html