Integer overflow in the object_custom function in ext/standard/var_unserializer.c in PHP before 5.4.34, 5.5.x before 5.5.18, and 5.6.x before 5.6.2 allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via an argument to the unserialize function that triggers calculation of a large length value.
https://support.apple.com/HT204659
https://bugzilla.redhat.com/show_bug.cgi?id=1154500
http://www.ubuntu.com/usn/USN-2391-1
http://www.securityfocus.com/bid/70611
http://www.oracle.com/technetwork/topics/security/bulletinjul2015-2511963.html
http://www.debian.org/security/2014/dsa-3064
http://secunia.com/advisories/61982
http://secunia.com/advisories/61970
http://secunia.com/advisories/61763
http://secunia.com/advisories/60699
http://secunia.com/advisories/60630
http://secunia.com/advisories/59967
http://rhn.redhat.com/errata/RHSA-2014-1824.html
http://rhn.redhat.com/errata/RHSA-2014-1768.html
http://rhn.redhat.com/errata/RHSA-2014-1767.html
http://rhn.redhat.com/errata/RHSA-2014-1766.html
http://rhn.redhat.com/errata/RHSA-2014-1765.html
http://php.net/ChangeLog-5.php
http://lists.opensuse.org/opensuse-updates/2015-01/msg00006.html
http://lists.opensuse.org/opensuse-updates/2014-11/msg00034.html
http://lists.opensuse.org/opensuse-updates/2014-11/msg00024.html
http://lists.apple.com/archives/security-announce/2015/Apr/msg00001.html
http://linux.oracle.com/errata/ELSA-2014-1768.html
http://linux.oracle.com/errata/ELSA-2014-1767.html
http://git.php.net/?p=php-src.git%3Ba=commit%3Bh=56754a7f9eba0e4f559b6ca081d9f2a447b3f159