Xen PCI Device IO Port Space BUG() Trigger Vulnerability

Publication date: 2026-09-08

Last updated on: 2026-09-10

Assigner: Xen Project

Description

A guest with a PCI device assigned that has at least a BAR on the IO port space can trigger a BUG() in Xen.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-08

Last Modified

2026-09-10

Generated

2026-09-29

AI Q&A

2026-09-10

EPSS Evaluated

2026-09-27

NVD

CVE-2026-79602

Affected Vendors & Products

Vendor	Product	Version / Range
xen	xen	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-119	The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.

Attack-Flow Graph

Executive Summary

This vulnerability allows a guest user with a PCI device assigned to a system running Xen to trigger a kernel bug (BUG()) in Xen. This occurs if the PCI device has at least one IO port space BAR (Base Address Register).

Impact Analysis

If exploited, this vulnerability could cause the Xen hypervisor to crash, leading to a denial of service (DoS) for all guests on the system. It may also allow guest users to gain unauthorized access or escalate privileges.

Mitigation Strategies

Remove or disable PCI device assignment to untrusted guests in Xen configurations. Update Xen to the latest patched version if available.

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