CVE-2026-79602: x86: improper handling of HVM emulation return codes
Published Sep 8, 2026
·Updated
A guest with a PCI device assigned that has at least a BAR on the IO port space can trigger a BUG() in Xen.
Affected Software
1 affected component
XEN Xen
Event History
Sep 8, 2026
CVE Published
via MITRE·12:11 PM
Data Sourced
via MITRE·12:11 PM
Description
Data Sourced
via NVD·01:17 PM
Description
Frequently Asked Questions
1
Which guest configurations are exposed to this issue?
A guest is exposed when it has an assigned PCI device with at least one BAR in I/O port space. The provided information does not establish that guests without such a device assignment are affected.
2
What does an attacker need to do to trigger the failure?
An attacker needs control of a guest that has the affected PCI device assignment and can cause the relevant HVM emulation path to handle the I/O-port BAR. Triggering it can cause Xen to hit a BUG().
3
What is the observable impact if exploitation succeeds?
The stated impact is a Xen BUG() condition. No further details about host availability, guest escape, data exposure, or persistence are provided.