Buffer overflow in the vnc_refresh_server_surface function in the VNC display driver in QEMU before 2.4.0.1 allows guest users to cause a denial of service (heap memory corruption and process crash) or possibly execute arbitrary code on the host via unspecified vectors, related to refreshing the server display surface.
http://lists.fedoraproject.org/pipermail/package-announce/2015-October/169039.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-September/165484.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-September/166798.html
http://rhn.redhat.com/errata/RHSA-2015-1772.html
http://rhn.redhat.com/errata/RHSA-2015-1837.html
https://lists.gnu.org/archive/html/qemu-devel/2015-08/msg02495.html
https://lists.gnu.org/archive/html/qemu-devel/2015-09/msg05832.html
https://security.gentoo.org/glsa/201602-01
http://www.debian.org/security/2015/dsa-3348