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. CREATE(Triage):(User=admin) CVE-2019-20838 (https://nvd.nist.gov/vuln/detail/CVE-2019-20838)