CVE-2026-42492 — vIRQ event channel binding may break Xenstore

Description (CNA)

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 (CNA)

Vendor / product	Versions
Xen / Xen	unknown consult Xen advisory XSA-496

CWE

No CWE identifiers supplied.

References

https://xenbits.xenproject.org/xsa/advisory-496.html

ADP enrichment

CVE

No English description supplied.

http://xenbits.xen.org/xsa/advisory-496.html
http://www.openwall.com/lists/oss-security/2026/07/28/13

CISA-ADP

No English description supplied.

No references supplied.