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.
CVE-2019-20454
CVSS base score
7.5 (v3.1)
Severity
HIGH
Attack vector
Network
Weakness
CWE-125
Last modified
November 2, 2026
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
pcre pcre2
fedoraproject fedora
splunk universal forwarder
References
- bugs.exim.org Issue Tracking, Permissions Required, Third Party Advisory
- bugs.php.net Exploit, Issue Tracking, Third Party Advisory
- bugzilla.redhat.com Issue Tracking, Patch, Third Party Advisory
- lists.debian.org Mailing List, Third Party Advisory
- lists.fedoraproject.org Mailing List, Third Party Advisory
- security.gentoo.org Third Party Advisory
- vcs.pcre.org Broken Link, Patch
- bugs.exim.org Issue Tracking, Permissions Required, Third Party Advisory
- bugs.php.net Exploit, Issue Tracking, Third Party Advisory
- bugzilla.redhat.com Issue Tracking, Patch, Third Party Advisory