Quick emulator (QEMU) before 2.8 built with the Cirrus CLGD 54xx VGA Emulator support is vulnerable to an out-of-bounds access issue. The issue could occur while copying VGA data in cirrus_bitblt_cputovideo. A privileged user inside guest could use this flaw to crash the QEMU process OR potentially execute arbitrary code on host with privileges of the QEMU process.