CVE-2026-42490
MEDIUMDescription
[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] To create and manage guests, domctl operations are used by the control domain, a possible Xenstore domain, or by a domain controlling a particular guest. Some of these operations may not be executed in parallel, so a system-wide lock is used. The way that lock is acquired is, however, not providing any fairness. This is CVE-2026-42489. Furthermore, with XSM/Flask in use, the lock acquire will, for some operations, occur ahead of any permission checking. This is CVE-2026-42490.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Exploit Intelligence
Low risk: more likely to be exploited than 10% of all known CVEs.
References
Related Vulnerabilities
Other CWE-667 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2019-10072 | High | 7.5 | 73% | - | Fix |
| CVE-2002-1850 | High | 7.5 | 17% | - | Fix |
| CVE-2009-2699 | High | 7.5 | 14% | - | Fix |
| CVE-2004-0174 | High | 7.5 | 12% | - | - |
| CVE-2009-4272 | High | 7.5 | 11% | - | - |
| CVE-2020-24606 | High | 8.6 | 5.2% | - | Fix |
Common questions
How do I fix CVE-2026-42490?
Upgrade xen on debian 13 to 4.20.3+127-gc42374a105-0+deb13u1 or later.
Is CVE-2026-42490 being actively exploited?
Not that we know of. CVE-2026-42490 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.20% is the estimated probability that it will be exploited in the next 30 days. That is higher than 10% of all scored CVEs.
How severe is CVE-2026-42490?
CVE-2026-42490 has a CVSS v3 base score of 6.5, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-42490 affect?
Published advisories record a fix for xen (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-42490
Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-22.