Expat allows context-dependent attackers to cause a denial of service (crash) or possibly execute arbitrary code via a malformed input document, which triggers a buffer overflow.
lists.apple.com/archives/security-announce/2016/Jul/msg00000.html
lists.opensuse.org/opensuse-security-announce/2016-05/msg00064.html
lists.opensuse.org/opensuse-security-announce/2016-06/msg00006.html
lists.opensuse.org/opensuse-security-announce/2016-06/msg00007.html
lists.opensuse.org/opensuse-security-announce/2016-06/msg00010.html
lists.opensuse.org/opensuse-security-announce/2016-08/msg00004.html
lists.opensuse.org/opensuse-security-announce/2016-08/msg00029.html
packetstormsecurity.com/files/141350/ESET-Endpoint-Antivirus-6-Remote-Code-Execution.html
rhn.redhat.com/errata/RHSA-2016-2824.html
seclists.org/fulldisclosure/2017/Feb/68
support.eset.com/ca6333/
www.debian.org/security/2016/dsa-3582
www.mozilla.org/security/announce/2016/mfsa2016-68.html
www.openwall.com/lists/oss-security/2016/05/17/12
www.oracle.com/technetwork/security-advisory/cpujul2018-4258247.html
www.oracle.com/technetwork/topics/security/bulletinjul2016-3090568.html
www.securityfocus.com/bid/90729
www.securitytracker.com/id/1036348
www.securitytracker.com/id/1036415
www.securitytracker.com/id/1037705
www.ubuntu.com/usn/USN-2983-1
www.ubuntu.com/usn/USN-3044-1
access.redhat.com/errata/RHSA-2018:2486
bugzilla.mozilla.org/show_bug.cgi?id=1236923
bugzilla.redhat.com/show_bug.cgi?id=1296102
kc.mcafee.com/corporate/index?page=content&id=SB10365
security.gentoo.org/glsa/201701-21
source.android.com/security/bulletin/2016-11-01.html
support.apple.com/HT206903
www.tenable.com/security/tns-2016-20