libpcre in PCRE before 8.43 allows a subject buffer over-read in JIT when UTF is disabled, and \X or \R has more than one fixed quantifier, a related issue to CVE-2019-20454.
In PCRE 8.41, the OP_KETRMAX feature in the match function in pcre_exec.c allows stack exhaustion (uncontrolled recursion) when processing a crafted regular expression.