Xen 4.6.3-15 packages for CentOS 6 and CentOS 7 are on their way through the build system. They should show up in centos-virt-testing in a few hours, and in the main mirrors tomorrow morning (God willing). These contain several critical updates; users are encouraged to update as soon as possible. XSA 220 unfortunately had several dependencies on changes included in 4.6.4 and 4.6.5. This particular vulnerability is slightly lower priorty; so I have queued up an update to 4.6.5 which includes this patch. Once 4.6.3-15 is tagged for release, I'll start building 4.6.5 put it in centos-virt-testing for people to test. -George