PCRE before 8.38 mishandles the [: and \\ substrings in character classes, which allows remote attackers to cause a denial of service (uninitialized memory read) or possibly have unspecified other impact via a crafted regular expression, as demonstrated by a JavaScript RegExp object encountered by Konqueror.

PCRE before 8.38 mishandles the /(?:|a|){100}x/ pattern and related patterns, which allows remote attackers to cause a denial of service (infinite recursion) or possibly have unspecified other impact via a crafted regular expression, as demonstrated by a JavaScript RegExp object encountered by Konqueror.

PCRE before 8.38 mishandles (?123) subroutine calls and related subroutine calls, which allows remote attackers to cause a denial of service (integer overflow) or possibly have unspecified other impact via a crafted regular expression, as demonstrated by a JavaScript RegExp object encountered by Konqueror.

PCRE before 8.38 mishandles the interaction of lookbehind assertions and mutually recursive subpatterns, 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.

PCRE before 8.38 mishandles certain repeated conditional groups, 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.