Xen 4.2.1: mercurial repository (tag RELEASE-4.2.1) or via the Xen 4.2.1 download page on xen.org.
Xen 4.1.4: mercurial repository (tag RELEASE-4.1.4) or via the Xen 4.1.4 download page on xen.org.
We recommend that all users of Xen 4.2.0 upgrade to Xen 4.2.1 and that users of the 4.0 and 4.1 stable series upgrade to Xen 4.1.4.
The Xen 4.2.1 release fixes the following critical vulnerabilities: We recommend to all users of Xen 4.2.0 to upgrade to Xen 4.2.1.
The Xen 4.1.4 release contains fixes for the following critical vulnerabilities: We recommend to all users of the 4.0 and 4.1 stable series to upgrade to Xen 4.1.4.