libspice, as used in QEMU-KVM in Red Hat Enterprise Virtualization Hypervisor (aka RHEV-H or rhev-hypervisor) before 5.5-2.2 and possibly other products, allows guest OS users to read from or write to arbitrary QEMU memory by modifying the address that is used by Cairo for memory mappings.
Improper Restriction of Operations within the Bounds of a Memory Buffer The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.