An issue was discovered in PHP before 5.6.40, 7.x before 7.1.26, 7.2.x before 7.2.14, and 7.3.x before 7.3.1. A number of heap-based buffer over-read instances are present in mbstring regular expression functions when supplied with invalid multibyte data. These occur in ext/mbstring/oniguruma/regcomp.c, ext/mbstring/oniguruma/regexec.c, ext/mbstring/oniguruma/regparse.c, ext/mbstring/oniguruma/enc/unicode.c, and ext/mbstring/oniguruma/src/utf32_be.c when a multibyte regular expression pattern contains invalid multibyte sequences.
https://www.debian.org/security/2019/dsa-4398
https://usn.ubuntu.com/3902-2/
https://usn.ubuntu.com/3902-1/
https://support.f5.com/csp/article/K06372014
https://security.netapp.com/advisory/ntap-20190321-0001/
https://bugs.php.net/bug.php?id=77418
https://bugs.php.net/bug.php?id=77394
https://bugs.php.net/bug.php?id=77385
https://bugs.php.net/bug.php?id=77382
https://bugs.php.net/bug.php?id=77381
https://bugs.php.net/bug.php?id=77371
https://bugs.php.net/bug.php?id=77370
https://access.redhat.com/errata/RHSA-2019:3299
https://access.redhat.com/errata/RHSA-2019:2519
http://www.securityfocus.com/bid/107156
http://lists.opensuse.org/opensuse-security-announce/2019-06/msg00044.html
http://lists.opensuse.org/opensuse-security-announce/2019-06/msg00041.html
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00104.html
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00083.html