7.5

CVE-2026-42492: vIRQ event channel binding may break Xenstore

Deferred
AliasesALPINE-CVE-2026-42492UBUNTU-CVE-2026-42492DEBIAN-CVE-2026-42492
Published 28-07-2026Last modified 28-07-2026

Vulnerability summary

CVE-2026-42492 is a high (CVSS 7.5) Incomplete Cleanup vulnerability in xen. EPSS estimates a 0.61% chance of exploitation in the next 30 days, higher than 49.2% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.61%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
OPENSUSE-SU-2026:11441-1

Timeline

  1. 28-07-2026
    PublishedVulnerability first disclosed.
  2. 28-07-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.61%

Chance of exploitation in the next 30 days

Percentile

49%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.61% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Alpine1 product
  • xen< 4.21.2-r0
Debian1 product
  • xenAll versions (No fix recorded)
Ubuntu1 product
  • xenAll versions (No fix recorded)

3 vendors · 3 products

References

8 links