The mozilla::dom::TextTrack::AddCue function in Mozilla Firefox before 29.0 and SeaMonkey before 2.26 does not properly perform garbage collection for Text Track Manager variables, which allows remote attackers to execute arbitrary code or cause a denial of service (use-after-free and heap memory corruption) via a crafted VIDEO element in an HTML document.
https://security.gentoo.org/glsa/201504-01
https://bugzilla.mozilla.org/show_bug.cgi?id=989210
http://www.ubuntu.com/usn/USN-2185-1
http://www.securitytracker.com/id/1030164
http://www.securitytracker.com/id/1030163
http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
http://www.mozilla.org/security/announce/2014/mfsa2014-39.html
http://secunia.com/advisories/59866
http://lists.opensuse.org/opensuse-updates/2014-05/msg00033.html
http://lists.opensuse.org/opensuse-updates/2014-05/msg00010.html
http://lists.fedoraproject.org/pipermail/package-announce/2014-May/132437.html