An issue was discovered in PHP before 5.6.36, 7.0.x before 7.0.30, 7.1.x before 7.1.17, and 7.2.x before 7.2.5. An infinite loop exists in ext/iconv/iconv.c because the iconv stream filter does not reject invalid multibyte sequences.
https://www.tenable.com/security/tns-2018-12
https://www.debian.org/security/2018/dsa-4240
https://usn.ubuntu.com/3646-1/
https://security.netapp.com/advisory/ntap-20180607-0003/
https://security.gentoo.org/glsa/201812-01
https://lists.debian.org/debian-lts-announce/2018/06/msg00005.html
https://bugs.php.net/bug.php?id=76249
https://access.redhat.com/errata/RHSA-2019:2519
http://www.securitytracker.com/id/1040807
http://www.securityfocus.com/bid/104019