We are pleased to announce the release of Xen 4.3.3. This is available immediately from its git repository http://xenbits.xen.org/gitweb/?p=xen.git;a=shortlog;h=refs/heads/stable-4.3 (tag RELEASE-4.3.3)
This release fixes the following critical vulnerabilities:

CVE-2014-2599 / XSA-89 HVMOP_set_mem_access is not preemptible
CVE-2014-3124 / XSA-92 HVMOP_set_mem_type allows invalid P2M entries to be created
CVE-2014-3967,CVE-2014-3968 / XSA-96 Vulnerabilities in HVM MSI injection
CVE-2014-4021 / XSA-100 Hypervisor heap contents leaked to guests Additionally a workaround for CVE-2013-3495 / XSA-59 (Intel VT-d Interrupt Remapping engines can be evaded by native NMI interrupts) has been put in place. However, at this point we can’t guarantee that all affected chipsets are being covered; Intel is working diligently on providing us with a complete list.

Apart from those fixes there are many further bug fixes and improvements. We recommend all users of the 4.3 stable series to update to this latest point release.