CVE-2016-6259: Citrix Xenserver

Medium severity, CVSS 6.2. EPSS: 0.6% chance of exploitation in the next 30 days.

Xen 4.5.x through 4.7.x do not implement Supervisor Mode Access Prevention (SMAP) whitelisting in 32-bit exception and event delivery, which allows local 32-bit PV guest OS kernels to cause a denial of service (hypervisor and VM crash) by triggering a safety check.

Affected products

• Citrix Xenserver: version 6.0 only; version 6.0.2 only; version 6.1 only; version 6.2.0 only; version 6.5.0 only; version 7.0 only
• Xen Xen: version 4.5.0 only; version 4.5.1 only; version 4.5.2 only; version 4.5.3 only; version 4.6.0 only; version 4.6.1 only; …

Published 2016-08-02. Last modified 2026-06-17.