PCRE before 8.38 mishandles the /(?=di(?<=(?1))|(?=(.))))/ pattern and related patterns with an unmatched closing parenthesis, which allows remote attackers to…

PCRE before 8.38 mishandles the /(?=di(?<=(?1))|(?=(.))))/ pattern and related patterns with an unmatched closing parenthesis, which allows remote attackers to cause a denial of service (buffer overflow) or possibly have unspecified other impact via a crafted regular expression, as demonstrated by a JavaScript RegExp object encountered by Konqueror.