Multiple use-after-free vulnerabilities in PHP before 5.4.45, 5.5.x before 5.5.29, and 5.6.x before 5.6.13 allow remote attackers to execute arbitrary code via vectors related to (1) the Serializable interface, (2) the SplObjectStorage class, and (3) the SplDoublyLinkedList class, which are mishandled during unserialization.
https://security.gentoo.org/glsa/201606-10
https://bugs.php.net/bug.php?id=70366
https://bugs.php.net/bug.php?id=70365
https://bugs.php.net/bug.php?id=70172
http://www.securitytracker.com/id/1033548
http://www.securityfocus.com/bid/76649