CVE-2026-42492: Xen

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

Xenstore, to have an up-to-date picture of the entire system, wants to know of domains appearing and disappearing. To make this more robust, a new XEN_DOMCTL_get_domain_state was introduced. The management of the bitmap underlying that operation is tied into the binding of the VIRQ_DOM_EXC virtual IRQ. Unfortunately an error path there would tear down the bitmap even in cases when it wasn't set up. Unprivileged domains can trigger that error path.

Affected products

• Xen Xen

Published 2026-07-28. Last modified 2026-07-28.