libc++abi in Apple OS X before 10.11.6 allows attackers to execute arbitrary code in a privileged context or cause a denial of service (memory corruption) via a crafted app.
https://support.apple.com/HT206903
http://www.securitytracker.com/id/1036348
http://www.securityfocus.com/bid/91824
http://lists.apple.com/archives/security-announce/2016/Jul/msg00000.html