The php_wddx_process_data function in ext/wddx/wddx.c in PHP before 5.6.25 and 7.x before 7.0.10 allows remote attackers to cause a denial of service (segmentation fault) or possibly have unspecified other impact via an invalid ISO 8601 time value, as demonstrated by a wddx_deserialize call that mishandles a dateTime element in a wddxPacket XML document.
https://www.tenable.com/security/tns-2016-19
https://security.gentoo.org/glsa/201611-22
https://github.com/php/php-src/commit/426aeb2808955ee3d3f52e0cfb102834cdb836a5?w=1
http://www.securitytracker.com/id/1036680
http://www.securityfocus.com/bid/92758
http://www.php.net/ChangeLog-7.php
http://www.php.net/ChangeLog-5.php