An incomplete fix for CVE-2018-5748 that affects QEMU monitor leading to a resource exhaustion but now also triggered via QEMU guest agent.qemu/qemu_monitor.c in libvirt allows attackers to cause a denial of service via a large QEMU reply.An industry-wide issue was found in the way many modern microprocessor designs have implemented speculative execution of Load Store instructions . It relies on the presence of a precisely-defined instruction sequence in the privileged code as well as the fact that memory read from address to which a recent memory write has occurred may see an older value and subsequently cause an update into the microprocessor#039;s data cache even for speculatively executed instructions that never actually commit . As a result, an unprivileged attacker could use this flaw to read privileged memory by conducting targeted cache side-channel attacks.