CVE-2019-20454

An out-of-bounds read was discovered in PCRE before 10.34 when the pattern
\X is JIT compiled and used to match specially crafted subjects in non-UTF
mode. Applications that use PCRE to parse untrusted input may be vulnerable
to this flaw, which would allow an attacker to crash the application. The
flaw occurs in do_extuni_no_utf in pcre2_jit_compile.c.

Bugs

• <https://bugs.exim.org/show_bug.cgi?id=2421&gt;
• <https://bugs.php.net/bug.php?id=78338&gt;
• <https://bugzilla.redhat.com/show_bug.cgi?id=1735494&gt;