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. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-5094
