spl_array.c in the SPL extension in PHP before 5.5.37 and 5.6.x before 5.6.23 improperly interacts with the unserialize implementation and garbage collection, which allows remote attackers to execute arbitrary code or cause a denial of service (use-after-free and application crash) via crafted serialized data.
http://github.com/php/php-src/commit/3f627e580acfdaf0595ae3b115b8bec677f203ee?w=1
http://lists.apple.com/archives/security-announce/2016/Sep/msg00006.html
http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00004.html
http://lists.opensuse.org/opensuse-updates/2016-08/msg00003.html
http://php.net/ChangeLog-5.php
http://rhn.redhat.com/errata/RHSA-2016-2750.html
https://bugs.php.net/bug.php?id=72433
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05240731
https://support.apple.com/HT207170