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-2015-3797 and CVE-2015-3798.
https://www.exploit-db.com/exploits/38263/
https://support.apple.com/kb/HT205031
https://support.apple.com/kb/HT205030
http://www.securitytracker.com/id/1033275
http://www.securityfocus.com/bid/76343
http://lists.apple.com/archives/security-announce/2015/Aug/msg00002.html
http://lists.apple.com/archives/security-announce/2015/Aug/msg00001.html