ext/wddx/wddx.c in PHP before 5.6.28 and 7.x before 7.0.13 allows remote attackers to cause a denial of service (NULL pointer dereference) via crafted serialized data in a wddxPacket XML document, as demonstrated by a PDORow string. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-9934