The xmlDictAddString function in libxml2 before 2.9.4, as used in Apple iOS before 9.3.2, OS X before 10.11.5, tvOS before 9.2.1, and watchOS before 2.2.1, allows remote attackers to cause a denial of service (heap-based buffer over-read) via a crafted XML document.
https://www.tenable.com/security/tns-2016-18
https://www.debian.org/security/2016/dsa-3593
https://support.apple.com/HT206568
https://support.apple.com/HT206567
https://support.apple.com/HT206566
https://support.apple.com/HT206564
https://security.gentoo.org/glsa/201701-37
https://kc.mcafee.com/corporate/index?page=content&id=SB10170
https://git.gnome.org/browse/libxml2/commit/?id=a820dbeac29d330bae4be05d9ecd939ad6b4aa33
https://access.redhat.com/errata/RHSA-2016:1292
http://www.ubuntu.com/usn/USN-2994-1
http://www.securitytracker.com/id/1038623
http://www.securitytracker.com/id/1035890
http://www.securityfocus.com/bid/90691
http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html
http://www.oracle.com/technetwork/topics/security/linuxbulletinjul2016-3090544.html
http://www.oracle.com/technetwork/topics/security/bulletinjul2016-3090568.html
http://rhn.redhat.com/errata/RHSA-2016-2957.html
http://lists.apple.com/archives/security-announce/2016/May/msg00004.html
http://lists.apple.com/archives/security-announce/2016/May/msg00003.html
http://lists.apple.com/archives/security-announce/2016/May/msg00002.html
http://lists.apple.com/archives/security-announce/2016/May/msg00001.html