I/O Port Access Vulnerability in XEN Hypervisor by Xen Project
CVE-2026-42487

7.9HIGH

Key Information:

Vendor

Xen Project
Status
Xen Project
Vendor
CVE Published:
18 June 2026

What is CVE-2026-42487?

A vulnerability exists in the XEN hypervisor, where handling of guest I/O port accesses lacks necessary synchronization during list traversal. This issue arises from the dynamic management of translations by the device model through XEN_DOMCTL_ioport_mapping, resulting in potential race conditions. If not addressed, this could lead to unexpected behavior or compromised guest isolation.

Affected Version(s)

Xen consult Xen advisory XSA-491

References

https://xenbits.xenproject.org/xsa/advisory-491.html

CVSS V3.1

Score:
7.9
Severity:
HIGH
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

This issue was discovered by Jan Beulich of SUSE.
.