The GetCode_ function in gd_gif_in.c in GD 2.1.1 and earlier, as used in PHP before 5.5.21 and 5.6.x before 5.6.5, allows remote attackers to cause a denial of service (buffer over-read and application crash) via a crafted GIF image that is improperly handled by the gdImageCreateFromGif function.
http://advisories.mageia.org/MGASA-2015-0040.html
http://lists.apple.com/archives/security-announce/2015/Sep/msg00008.html
http://lists.opensuse.org/opensuse-security-announce/2015-05/msg00005.html
http://lists.opensuse.org/opensuse-updates/2015-04/msg00002.html
http://marc.info/?l=bugtraq&m=143403519711434&w=2
http://php.net/ChangeLog-5.php
http://rhn.redhat.com/errata/RHSA-2015-1053.html
http://rhn.redhat.com/errata/RHSA-2015-1066.html
http://rhn.redhat.com/errata/RHSA-2015-1135.html
http://rhn.redhat.com/errata/RHSA-2015-1218.html
https://bugs.php.net/bug.php?id=68601
https://bugzilla.redhat.com/show_bug.cgi?id=1188639
https://security.gentoo.org/glsa/201606-10
https://security.gentoo.org/glsa/201607-04
https://support.apple.com/HT205267
http://www.debian.org/security/2015/dsa-3215
http://www.mandriva.com/security/advisories?name=MDVSA-2015:153
http://www.oracle.com/technetwork/topics/security/bulletinapr2015-2511959.html
http://www.oracle.com/technetwork/topics/security/linuxbulletinjan2016-2867209.html