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. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-7295