CVE-2026-42492 (CVSS 7.5)

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.

Is your site exposed to CVE-2026-42492?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0046

Probability of exploitation

0.38%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-459 CWE-459

References

Other References

https://xenbits.xenproject.org/xsa/advisory-496.html http://www.openwall.com/lists/oss-security/2026/07/28/13 http://xenbits.xen.org/xsa/advisory-496.html

Frequently Asked Questions

What is CVE-2026-42492? +

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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-42492? +

CVE-2026-42492 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0046, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-42492? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-6338

There is an incomplete cleanup vulnerability in Qt Network's Schannel support on Windows which can lead to a Denial of …

CVE-2026-0427

Improper cleanup of shared register resources in GPU firmware could allow an admin-privileged attacker from a Guest Virtual machine (VM) …

CVE-2026-77761

A parser state isolation vulnerability in misp-stix could cause data from a previously processed STIX document to be retained and …

CVE-2026-106366

Incomplete cleanup in CustomTabs in Google Chrome on on Android prior to 155.0.8059.39 allowed a remote attacker to bypass web …

CVE-2026-15390

Das U-Boot with CONFIG_IP_DEFRAG=y parameter fails to clear IP reassembly state after delivering a complete datagram. An attacker who can …

CVE-2026-34263 9.6

Due to improper Spring Security configuration, SAP Commerce Cloud allows an unauthenticated user to perform malicious input injection, resulting in …

CVE-2026-42492