Updated libvirt packages fix security vulnerabilities:
An information leak which allowed to retrieve the guest hostname under readonly mode (CVE-2019-3886).
Wrong permissions in systemd admin-sock due to missing SocketMode parameter (CVE-2019-10132).
Arbitrary file read/exec via virDomainSaveImageGetXMLDesc API (CVE-2019-10161).
virDomainManagedSaveDefineXML API exposed to readonly clients (CVE-2019-10166).
Arbitrary command execution via virConnectGetDomainCapabilities API (CVE-2019-10167).
Arbitrary command execution via virConnectBaselineHypervisorCPU and virConnectCompareHypervisorCPU APIs (CVE-2019-10168).
Also, this update contains the libvirt adjustments, that pass through the new 'md-clear' CPU flag, to help address Intel CPU speculative execution flaws.