The following updates address security issues or other critical issues in Citrix XenServer products, and are made available to users of all editions.

Other updates are available only to users of Enterprise Edition and Standard Edition with valid support and maintenance agreements.

For Citrix XenServer v4 (4.0.1):

•  XenSource 4.0.1 Hotfix 2007-001
  This security update fixes a vulnerability in the Citrix XenServer v4 line of products that can allow root escalation from virtual machines in domain 0.
•  XenSource 4.0.1 Hotfix 2007-002
  This hotfix addresses a stability issue in the Citrix XenServer v4 line of products that can cause uploads of patches larger than 64KB to fail.
•  (Note: Hotfix 2007-003 was not released.)
•  XenSource 4.0.1 Hotfix 2007-004
  This hotfix addresses potential performance issues when running Citrix Presentation Server in Windows guests on XenServer 4.0.1.