Mozilla Firefox before 48.0 and Firefox ESR 45.x before 45.3 process JavaScript event-handler attributes of a MARQUEE element within a sandboxed IFRAME element that lacks the sandbox="allow-scripts" attribute value, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via a crafted web site.
https://security.gentoo.org/glsa/201701-15
https://bugzilla.mozilla.org/show_bug.cgi?id=1277475
http://www.ubuntu.com/usn/USN-3044-1
http://www.securitytracker.com/id/1036508
http://www.securityfocus.com/bid/92258
http://www.oracle.com/technetwork/topics/security/linuxbulletinjul2016-3090544.html
http://www.mozilla.org/security/announce/2016/mfsa2016-76.html
http://www.debian.org/security/2016/dsa-3640
http://rhn.redhat.com/errata/RHSA-2016-1551.html
http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00029.html
http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00004.html