CVE-2026-42490

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH confidence

Score 6.5 from GitHub Security Advisory published 2026-06-18. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

[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.

CVSS v3
6.5
EG Score
6.5(high)
EPSS
10.0%
KEV
Not listed

Published

June 18, 2026

Last Modified

June 22, 2026

Advisory Details (1)

Auto-updated Jun 21, 2026
No patch confirmed yet.
generic

XSA-492 - Xen Security Advisories

https://xenbits.xenproject.org/xsa/advisory-492.html

Vendor Advisories for CVE-2026-42490(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 22× in last 7d / 49× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-07 01:46 UTCEG score recompute
  2. 2026-07-07 01:45 UTCGHSA enrichment
  3. 2026-07-06 16:27 UTCEPSS rescore
  4. 2026-07-06 16:27 UTCEPSS rescore
  5. 2026-07-06 02:23 UTCEPSS rescore
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-05 23:33 UTCEG score recompute
  8. 2026-07-05 23:32 UTCGHSA enrichment
  9. 2026-07-05 02:30 UTCEPSS rescore
  10. 2026-07-04 21:20 UTCEG score recompute
  11. 2026-07-04 21:20 UTCGHSA enrichment
  12. 2026-07-04 06:31 UTCEPSS rescore
  13. 2026-07-03 19:08 UTCEG score recompute
  14. 2026-07-03 19:08 UTCGHSA enrichment
  15. 2026-07-02 16:56 UTCEG score recompute
  16. 2026-07-02 16:56 UTCGHSA enrichment
  17. 2026-07-01 15:06 UTCEPSS rescore
  18. 2026-07-01 14:44 UTCEG score recompute
  19. 2026-07-01 14:44 UTCGHSA enrichment
  20. 2026-06-30 23:22 UTCEPSS rescore
  21. 2026-06-30 12:32 UTCEG score recompute
  22. 2026-06-30 12:31 UTCGHSA enrichment
  23. 2026-06-29 14:06 UTCEPSS rescore
  24. 2026-06-29 10:19 UTCEG score recompute
  25. 2026-06-29 10:19 UTCGHSA enrichment
Show 24 more
  1. 2026-06-28 14:07 UTCEPSS rescore
  2. 2026-06-28 08:07 UTCEG score recompute
  3. 2026-06-28 08:07 UTCGHSA enrichment
  4. 2026-06-28 04:56 UTCEPSS rescore
  5. 2026-06-27 05:56 UTCEG score recompute
  6. 2026-06-27 05:56 UTCGHSA enrichment
  7. 2026-06-27 03:08 UTCEPSS rescore
  8. 2026-06-26 03:44 UTCEG score recompute
  9. 2026-06-26 03:44 UTCGHSA enrichment
  10. 2026-06-25 13:49 UTCEPSS rescore
  11. 2026-06-25 13:49 UTCEPSS rescore
  12. 2026-06-25 01:32 UTCEG score recompute
  13. 2026-06-25 01:31 UTCGHSA enrichment
  14. 2026-06-24 14:05 UTCEPSS rescore
  15. 2026-06-23 23:19 UTCEG score recompute
  16. 2026-06-23 23:19 UTCGHSA enrichment
  17. 2026-06-23 21:33 UTCEPSS rescore
  18. 2026-06-22 21:07 UTCEG score recompute
  19. 2026-06-22 21:07 UTCGHSA enrichment
  20. 2026-06-21 18:55 UTCEG score recompute▲ 6.50
  21. 2026-06-21 18:55 UTCGHSA enrichment
  22. 2026-06-18 17:24 UTCNVD updateCVSS v3 → 6.5 · severity → MEDIUM
  23. 2026-06-18 15:45 UTCEG score recompute
  24. 2026-06-18 15:44 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-42490?
CVE-2026-42490 is a medium vulnerability published on June 18, 2026. [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…
When was CVE-2026-42490 disclosed?
CVE-2026-42490 was first published in the National Vulnerability Database on June 18, 2026, with the most recent update on June 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42490 actively exploited?
CVE-2026-42490 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 10.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-42490?
CVE-2026-42490 has a CVSS v3.1 base score of 6.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-42490?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42490, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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