pcre: stack overflow caused by mishandled group empty match (8.38/11)

PCRE 7.8 and 8.32 through 8.37, and PCRE2 10.10 mishandle group empty matches, which might allow remote attackers to cause a denial of service stack-based buffer overflow via a crafted regular expression, as demonstrated by /^?:?1\.|^\\W?++$/...