The pcre_compile2 function in pcre_compile.c in PCRE 8.38 mishandles the /((?:F?+(?:^(?(R)a+\"){99}-))(?J)(?\'R\'(?\'R\'<((?\'RR\'(?\'R\'\){97)?J)?J)(?\'R\'(?\'R\'\){99|(:(?|(?\'R\')(\k\'R\')|((?\'R\')))H\'R\'R)(H\'R))))))/ pattern and related patterns with named subgroups, which allows remote attackers to cause a denial of service (heap-based buffer overflow) or possibly have unspecified other impact via a crafted regular expression, as demonstrated by a JavaScript RegExp object encountered by Konqueror.