CVE-2026-42487: Xen

High severity, CVSS 7.9. EPSS: 0.1% chance of exploitation in the next 30 days.

HVM guest I/O port accesses are subject to either emulation or at least translation. Translations are managed by the device model (via XEN_DOMCTL_ioport_mapping), and hence the linked list used may changed at any time. Traversal of those lists (while handling guest I/O port accesses) therefore needs synchronizing with updates, which was missing so far.

Affected products

• Xen Xen

Published 2026-06-18. Last modified 2026-06-22.