The template-validate command in OpenStack Orchestration API (Heat) before 2015.1.3 (kilo) and 5.0.x before 5.0.1 (liberty) allows remote authenticated users to cause a denial of service (memory consumption) or determine the existence of local files via the resource type in a template, as demonstrated by file:///dev/zero.
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.
The Floppy Disk Controller (FDC) in QEMU, as used in Xen 4.5.x and earlier and KVM, allows local guest users to cause a denial of service (out-of-bounds write and guest crash) or possibly execute arbitrary code via the (1) FD_CMD_READ_ID, (2) FD_CMD_DRIVE_SPECIFICATION_COMMAND, or other unspecified commands, aka VENOM.