CVE-2026-42492
vIRQ event channel binding may break Xenstore
Description
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.
INFO
Published Date :
July 28, 2026, 1:18 p.m.
Last Modified :
July 28, 2026, 2:16 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-42492
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update Xenstore to the latest version.
- Review Xenstore error handling logic.
- Ensure bitmap is managed correctly.
- Test domain state reporting.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-42492.
| URL | Resource |
|---|---|
| https://xenbits.xenproject.org/xsa/advisory-496.html | |
| http://xenbits.xen.org/xsa/advisory-496.html |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-42492 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-42492
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-42492 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-42492 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Jul. 28, 2026
Action Type Old Value New Value Added Reference http://xenbits.xen.org/xsa/advisory-496.html -
New CVE Received by [email protected]
Jul. 28, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Xen', 'product': 'Xen', 'versions': [{'status': 'unknown', 'version': 'consult Xen advisory XSA-496'}], 'defaultStatus': 'unknown'}] Added Description 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. Added Reference https://xenbits.xenproject.org/xsa/advisory-496.html