The TRE library in Libc in Apple iOS before 8.4.1 and OS X before 10.10.5 allows context-dependent attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted regular expression, a different vulnerability than CVE-2015-3796 and CVE-2015-3797.
lists.apple.com/archives/security-announce/2015/Aug/msg00001.html
lists.apple.com/archives/security-announce/2015/Aug/msg00002.html
www.securityfocus.com/bid/76343
www.securitytracker.com/id/1033275
code.google.com/p/google-security-research/issues/detail?id=429
support.apple.com/kb/HT205030
support.apple.com/kb/HT205031
www.exploit-db.com/exploits/38262/