As you may have already heard, an industry-wide issue was found in the way many modern microprocessor designs have implemented speculative execution of Load & Store instructions.
This issue is well described by CVE-2018-3639 announce available at https://access.redhat.com/security/cve/cve-2018-3639.

oVirt team has released right now an update of ovirt-engine to version 4.2.3.7 which add support for SSBD CPUs in order to mitigate the security issue.

If you are running oVirt on Red Hat Enterprise Linux, please apply updates described in https://access.redhat.com/security/cve/cve-2018-3639.

If you are running oVirt on CentOS Linux please apply updated described by:
CESA-2018:1629 Important CentOS 7 kernel Security Update  
CESA-2018:1632 Important CentOS 7 libvirt Security Update 
CESA-2018:1649 Important CentOS 7 java-1.8.0-openjdk Security Update  
CESA-2018:1648 Important CentOS 7 java-1.7.0-openjdk Security Update  

An update for qemu-kvm-ev has been also tagged for release and announced with
CESA-2018:1655 Important: qemu-kvm-ev security update  
but due to some issues in CentOS release process for Virt SIG content, it is not yet available on mirrors.
We are working with CentOS community to get the packages signed and published as soon as possible.
In the meanwhile you can still get the update package by enabling the test repository https://buildlogs.centos.org/centos/7/virt/x86_64/kvm-common/ on your systems or manually installing the package from the repository.

If you're running oVirt on a different Linux distribution, please check with your vendor for available updates. 

Please note that to fully mitigate this vulnerability, system administrators must apply both hardware “microcode” updates and software patches that enable new functionality.
At this time, microprocessor microcode will be delivered by the individual manufacturers.

The oVirt team recommends end users and systems administrator to apply any available updates as soon as practical.

Thanks,
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SANDRO BONAZZOLA

ASSOCIATE MANAGER, SOFTWARE ENGINEERING, EMEA ENG VIRTUALIZATION R&D

Red Hat EMEA

sbonazzo@redhat.com