CVE-2026-4740

HIGHPre-NVD 8.28.2—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.2 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.0%, top 98% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: cna:redhat, epss
8.2
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.2Exploit: NoneExposed: 0

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

A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM). Improper validation of Kubernetes client certificate renewal allows a managed cluster administrator to forge a client certificate that can be approved by the OCM controller. This enables cross-cluster privilege escalation and may allow an attacker to gain control over other managed clusters, including the hub cluster.

CVSS v3
8.2
EG Score
8.2(medium)
EPSS
1.6%
KEV
Not listed

Published

April 7, 2026

Last Modified

June 30, 2026

Advisory Details (3)

Auto-updated May 4, 2026
Patch available. Sources: redhat.
redhat

2450590 – (CVE-2026-4740) CVE-2026-4740 rhacm: Open Cluster Management (OCM): Cross-cluster privilege escalation via improper Kubernetes client certificate renewal validation

https://bugzilla.redhat.com/show_bug.cgi?id=2450590
generic

CVE-2026-4740 - Cross-cluster escalation in Red Hat ACM and Open Cluster Management

https://blog.arfevrier.fr/open-cluster-management-cross-cluster-escape/
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-4740

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
open-cluster-management.io/ocm—1.2.1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 33× 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. 2026-07-12 05:46 UTCEPSS rescore
  2. 2026-07-11 08:27 UTCEPSS rescore
  3. 2026-07-11 08:27 UTCEPSS rescore
  4. 2026-07-09 19:10 UTCEPSS rescore
  5. 2026-07-08 15:16 UTCEPSS rescore
  6. 2026-07-07 13:46 UTCEPSS rescore
  7. 2026-07-06 16:27 UTCEPSS rescore
  8. 2026-07-06 02:23 UTCEPSS rescore
  9. 2026-07-05 02:30 UTCEPSS rescore
  10. 2026-07-04 06:31 UTCEPSS rescore
  11. 2026-06-30 23:22 UTCEPSS rescore
  12. 2026-06-29 14:06 UTCEPSS rescore
  13. 2026-06-29 14:06 UTCEPSS rescore
  14. 2026-06-28 14:07 UTCEPSS rescore
  15. 2026-06-27 03:08 UTCEPSS rescore
  16. 2026-06-23 21:33 UTCEPSS rescore
  17. 2026-06-23 21:33 UTCEPSS rescore
  18. 2026-06-22 14:25 UTCEPSS rescore
  19. 2026-06-22 14:25 UTCEPSS rescore
  20. 2026-06-21 01:59 UTCEPSS rescore
  21. 2026-06-21 01:59 UTCEPSS rescore
  22. 2026-06-19 19:26 UTCEPSS rescore
  23. 2026-06-19 19:26 UTCEPSS rescore
  24. 2026-06-18 17:52 UTCEPSS rescore
  25. 2026-06-18 17:52 UTCEPSS rescore
Show 47 more
  1. 2026-06-17 17:53 UTCEPSS rescore
  2. 2026-06-16 17:53 UTCEPSS rescore
  3. 2026-06-15 17:49 UTCEPSS rescore
  4. 2026-06-15 17:49 UTCEPSS rescore
  5. 2026-06-14 23:18 UTCEPSS rescore
  6. 2026-06-13 23:00 UTCEPSS rescore
  7. 2026-06-12 23:12 UTCEPSS rescore
  8. 2026-06-12 23:12 UTCEPSS rescore
  9. 2026-06-11 21:25 UTCEG score recompute
  10. 2026-06-11 14:00 UTCEPSS rescore
  11. 2026-06-10 22:19 UTCEPSS rescore
  12. 2026-06-10 16:13 UTCEG score recompute
  13. 2026-06-10 13:22 UTCEPSS rescore
  14. 2026-06-10 03:02 UTCEG score recompute
  15. 2026-06-09 13:55 UTCEG score recompute
  16. 2026-06-08 14:17 UTCEPSS rescore
  17. 2026-06-08 14:17 UTCEPSS rescore
  18. 2026-06-08 12:34 UTCEG score recompute
  19. 2026-06-07 23:27 UTCEG score recompute
  20. 2026-06-07 10:19 UTCEG score recompute
  21. 2026-06-06 13:47 UTCEPSS rescore
  22. 2026-06-06 13:47 UTCEPSS rescore
  23. 2026-06-05 22:47 UTCEPSS rescore
  24. 2026-06-05 06:10 UTCEPSS rescore
  25. 2026-06-05 06:10 UTCEPSS rescore
  26. 2026-06-04 13:12 UTCEPSS rescore
  27. 2026-06-04 13:12 UTCEPSS rescore
  28. 2026-06-02 20:13 UTCEPSS rescore
  29. 2026-06-01 13:52 UTCEPSS rescore
  30. 2026-06-01 13:52 UTCEPSS rescore
  31. 2026-05-31 22:30 UTCEPSS rescore
  32. 2026-05-31 22:30 UTCEPSS rescore
  33. 2026-05-31 00:16 UTCEPSS rescore
  34. 2026-05-31 00:16 UTCEPSS rescore
  35. 2026-05-29 13:44 UTCEPSS rescore
  36. 2026-05-29 13:44 UTCEPSS rescore
  37. 2026-05-28 13:44 UTCEPSS rescore
  38. 2026-05-28 13:44 UTCEPSS rescore
  39. 2026-05-27 13:40 UTCEPSS rescore
  40. 2026-05-27 13:40 UTCEPSS rescore
  41. 2026-05-26 13:44 UTCEPSS rescore
  42. 2026-05-26 07:18 UTCEPSS rescore
  43. 2026-05-23 00:08 UTCEG score recompute
  44. 2026-05-21 22:43 UTCEPSS rescore
  45. 2026-05-20 22:38 UTCEPSS rescore
  46. 2026-05-20 18:44 UTCEG score recompute
  47. 2026-05-20 11:22 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-4740?
CVE-2026-4740 is a high vulnerability published on April 7, 2026. A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM). Improper validation of Kubernetes client certificate renewal allows a managed cluster administrator to forge a client certificate that can be approved by the OCM controller. This…
When was CVE-2026-4740 disclosed?
CVE-2026-4740 was first published in the National Vulnerability Database on April 7, 2026, with the most recent update on June 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-4740 actively exploited?
CVE-2026-4740 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-4740?
CVE-2026-4740 has a CVSS v3 base score of 8.2 (NVD).
How do I remediate CVE-2026-4740?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-4740, 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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