Integer overflow in the php_html_entities function in ext/standard/html.c in PHP before 5.5.36 and 5.6.x before 5.6.22 allows remote attackers to cause a denial of service or possibly have unspecified other impact by triggering a large output string from the htmlspecialchars function.
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05240731
https://github.com/php/php-src/commit/0da8b8b801f9276359262f1ef8274c7812d3dfda?w=1
https://bugs.php.net/bug.php?id=72135
http://www.securityfocus.com/bid/90857
http://www.openwall.com/lists/oss-security/2016/05/26/3
http://www.debian.org/security/2016/dsa-3602