The compile_bracket_matchingpath function in pcre_jit_compile.c in PCRE through 8.x before revision 1680 (e.g., the PHP 7.1.1 bundled version) allows remote attackers to cause a denial of service (out-of-bounds read and application crash) via a crafted regular expression. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2017-6004
