hw/virtio/virtio.c in the Virtual Network Device (virtio-net) support in QEMU, when big or mergeable receive buffers are not supported, allows remote attackers to cause a denial of service (guest network consumption) via a flood of jumbo frames on the (1) tuntap or (2) macvtap interface.
https://security.gentoo.org/glsa/201602-01
http://www.securityfocus.com/bid/82672
http://www.openwall.com/lists/oss-security/2015/09/18/9
http://www.openwall.com/lists/oss-security/2015/09/18/5
http://www.debian.org/security/2016/dsa-3471
http://www.debian.org/security/2016/dsa-3470
http://www.debian.org/security/2016/dsa-3469
http://lists.fedoraproject.org/pipermail/package-announce/2015-October/169802.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-October/169767.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-October/169624.html