PCRE before 8.36 mishandles the /(((a2)|(a*)g<-1>))*/ pattern and related patterns with certain internal recursive back references, which allows remote attackers to cause a denial of service (segmentation fault) or possibly have unspecified other impact via a crafted regular expression, as demonstrated by a JavaScript RegExp object encountered by Konqueror.

PCRE before 8.36 mishandles the /((?(R)a|(?1)))+/ pattern and related patterns with certain recursion, which allows remote attackers to cause a denial of service (segmentation fault) or possibly have unspecified other impact via a crafted regular expression, as demonstrated by a JavaScript RegExp object encountered by Konqueror.

The pcre_exec function in pcre_exec.c in PCRE before 8.38 mishandles a // pattern with a 1 string, 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.

The compile_regex function in pcre_compile.c in PCRE before 8.38 and pcre2_compile.c in PCRE2 before 10.2x mishandles the /(?J:(?|(:(?|(?’R’)(k’R’)|((?’R’)))H’Rk’Rf)|s(?’R’))))/ and /(?J:(?|(:(?|(?’R’)(z(?|(?’R’)(k’R’)|((?’R’)))k’R’)|((?’R’)))H’Ak’Rf)|s(?’R’)))/ patterns, and related patterns with certain group references, 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.

The match function in pcre_exec.c in PCRE before 8.37 mishandles the /(?:((abcd))|(((?:(?:(?:(?:abc|(?:abcdef))))b)abcdefghi)abc)|((*ACCEPT)))/ pattern and related patterns involving (*ACCEPT), which allows remote attackers to obtain sensitive information from process memory or cause a denial of service (partially initialized memory and application crash) via a crafted regular expression, as demonstrated by a JavaScript RegExp object encountered by Konqueror, aka ZDI-CAN-2547.

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.

PCRE before 8.38 mishandles the /(?J)(?’d'(?’d’g{d}))/ pattern and related patterns with certain recursive back references, 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, a related issue to CVE-2015-8392 and CVE-2015-8395.

PCRE before 8.38 mishandles the /(?|(k’Pm’)|(?’Pm’))/ pattern and related patterns with certain forward references, 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 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 (?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.