QEMU (aka Quick Emulator) built with the Virtio GPU Device emulator support is vulnerable to a memory leakage issue. It could occur while updating the cursor data in update_cursor_data_virgl. A guest user/process could use this flaw to leak host memory bytes, resulting in DoS for a host.
https://security.gentoo.org/glsa/201701-49
https://lists.gnu.org/archive/html/qemu-devel/2016-11/msg00029.html
http://www.securityfocus.com/bid/94765