The VNC websocket frame decoder in QEMU allows remote attackers to cause a denial of service (memory and CPU consumption) via a large (1) websocket payload or (2) HTTP headers section.
https://security.gentoo.org/glsa/201602-01
https://lists.gnu.org/archive/html/qemu-devel/2015-03/msg04896.html
https://lists.gnu.org/archive/html/qemu-devel/2015-03/msg04895.html
https://lists.gnu.org/archive/html/qemu-devel/2015-03/msg04894.html
http://www.ubuntu.com/usn/USN-2608-1
http://www.securitytracker.com/id/1033975
http://www.securityfocus.com/bid/73303
http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
http://www.openwall.com/lists/oss-security/2015/04/09/6
http://www.openwall.com/lists/oss-security/2015/03/24/9
http://www.debian.org/security/2015/dsa-3259
http://rhn.redhat.com/errata/RHSA-2015-1943.html
http://rhn.redhat.com/errata/RHSA-2015-1931.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-April/155196.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-April/154656.html