xen-4.4.3-9 and kernel-3.18.21-17 (unsigneg) are now on buildlogs.centos.org, and signed packages should be making their way through the mirror system in the near future.

Updated package sources can be found in the virt sig area on CentOS:

https://github.com/CentOS-virt7/xen https://github.com/CentOS-virt7/xen-kernel

The packages contain updates for XSAs 155, 157, 164, 165, and 166 (released today), as well as patches for XSA-142 and an update to XSA-158.

For those urgent to install the updated packages, you can get them from buildlogs by enabling the centos-virt-xen-testing repository:

yum --enablerepo=centos-virt-xen-testing update

Please report any issues here on the list.

-George