CVE-2013-4361: Xen

Low severity, CVSS 2.1. EPSS: 0.4% chance of exploitation in the next 30 days.

The fbld instruction emulation in Xen 3.3.x through 4.3.x does not use the correct variable for the source effective address, which allows local HVM guests to obtain hypervisor stack information by reading the values used by the instruction.

Affected products

• Xen Xen: version 3.3.0 only; version 3.3.1 only; version 3.3.2 only; version 3.4.0 only; version 3.4.1 only; version 3.4.2 only; …

Published 2013-10-01. Last modified 2026-06-16.