qemu/qemu_driver.c in libvirt before 6.0.0 mishandles the holding of a monitor job during a query to a guest agent, which allows attackers to cause a denial of service (API blockage).
bugs.debian.org/cgi-bin/bugreport.cgi?bug=953078
bugzilla.redhat.com/show_bug.cgi?id=1809740
libvirt.org/git/?p=libvirt.git%3Ba=commit%3Bh=a663a860819287e041c3de672aad1d8543098ecc
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/D5GE6ISYUL3CIWO3FQRUGMKTKP2NYED2/
security-tracker.debian.org/tracker/CVE-2019-20485
www.mail-archive.com/debian-bugs-dist%40lists.debian.org/msg1730509.html