CVE-2026-42492

HIGH

vIRQ event channel binding may break Xenstore

Title source: cna
STIX 2.1

Description

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.

Scores

CVSS v3 7.5
EPSS 0.0048
EPSS Percentile 38.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-459
Status published
Products (1)
Xen/Xen consult Xen advisory XSA-496
Published Jul 28, 2026
Tracked Since Jul 28, 2026