CVE-2011-2901: Off-by-one error in the __addr_ok macro in Xen 3.3 and earlier allows local 64 bit PV guest administrators...

Security readout for executives and security teams

This flaw could let an administrator inside a 64-bit Xen paravirtualized guest crash the physical host. The business risk is service outage, especially in shared virtualization environments. The sources do not show data theft, privilege escalation, or confirmed active exploitation. Exposure appears limited to Xen 3.3 and earlier, specifically 64-bit paravirtualized guest deployments. Risk is highest where guest administrators are untrusted or tenants are separated by the same Xen host. Treat as a legacy virtualization availability risk. It warrants prompt remediation if affected Xen hosts remain in production, but urgency is lower where no Xen 3.3-or-earlier PV environment exists. Mitigation focus: Identify Xen hosts running version 3.3 or earlier.; Apply relevant vendor security updates from Red Hat, Gentoo, or Xen guidance.; Migrate unsupported Xen deployments to a supported release..

Prepared

Jun 14, 2026, 15:32 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.