CVE-2026-4740

HIGHPre-NVD 8.28.2—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.2 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1%, top 96% 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: epss, secondary
Trending — 3 sources updated this week
8.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.2Exploit: None knownExposed: 0

A fix is available — apply it.

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)
EG Risk
37(Track)
EG Risk 37/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity82% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
4%
KEV
Not listed

Published

April 7, 2026

Last Modified

August 25, 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

Vendor Advisories for CVE-2026-4740(5)

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

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatmulticluster-engine/registration-rhel9:17774783902026-05-05redhat
redhatmulticluster-engine/registration-rhel9:17768811642026-05-04redhat
redhatmulticluster-engine/registration-rhel9:17764450952026-04-28redhat
redhatmulticluster-engine/registration-rhel9:17759771802026-04-22redhat
redhatmulticluster-engine/registration-rhel9:17756387262026-04-15redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

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 15× in last 7d / 108× 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.

Showing the most recent 100 of 193 total refreshes for this CVE.

  1. 2026-08-30 19:17 UTCEPSS rescore
  2. 2026-08-30 01:22 UTCEPSS rescore
  3. 2026-08-28 21:41 UTCEPSS rescore
  4. 2026-08-27 14:25 UTCEPSS rescore
  5. 2026-08-26 14:46 UTCEPSS rescore
  6. 2026-08-25 13:49 UTCEPSS rescore
  7. 2026-08-25 13:25 UTCEG score recompute
  8. 2026-08-25 13:25 UTCVendor advisory
  9. 2026-08-25 12:22 UTCEG score recompute
  10. 2026-08-25 12:22 UTCVendor advisory
  11. 2026-08-25 06:30 UTCVendor advisory
  12. 2026-08-25 05:25 UTCEG score recompute
  13. 2026-08-25 05:25 UTCVendor advisory
  14. 2026-08-25 05:00 UTCEG score recompute
  15. 2026-08-25 05:00 UTCVendor advisory
  16. 2026-08-24 13:31 UTCEG score recompute
  17. 2026-08-24 13:31 UTCVendor advisory
  18. 2026-08-24 12:27 UTCEG score recompute
  19. 2026-08-24 12:27 UTCVendor advisory
  20. 2026-08-24 08:33 UTCEG score recompute
  21. 2026-08-24 08:33 UTCVendor advisory
  22. 2026-08-24 07:43 UTCEG score recompute
  23. 2026-08-24 07:43 UTCVendor advisory
  24. 2026-08-23 12:18 UTCEG score recompute
  25. 2026-08-23 12:18 UTCVendor advisory
Show 75 more
  1. 2026-08-23 11:46 UTCEG score recompute
  2. 2026-08-23 11:46 UTCVendor advisory
  3. 2026-08-23 00:19 UTCEPSS rescore
  4. 2026-08-21 23:49 UTCEPSS rescore
  5. 2026-08-20 22:55 UTCEPSS rescore
  6. 2026-08-20 13:59 UTCEG score recompute
  7. 2026-08-20 13:59 UTCVendor advisory
  8. 2026-08-20 12:45 UTCEG score recompute
  9. 2026-08-20 12:45 UTCVendor advisory
  10. 2026-08-19 17:04 UTCEPSS rescore
  11. 2026-08-19 13:25 UTCEG score recompute
  12. 2026-08-19 13:25 UTCVendor advisory
  13. 2026-08-19 12:12 UTCEG score recompute
  14. 2026-08-19 12:12 UTCVendor advisory
  15. 2026-08-19 00:20 UTCVendor advisory
  16. 2026-08-18 23:23 UTCEG score recompute
  17. 2026-08-18 23:23 UTCVendor advisory
  18. 2026-08-18 23:08 UTCEG score recompute
  19. 2026-08-18 23:08 UTCVendor advisory
  20. 2026-08-18 13:48 UTCEPSS rescore
  21. 2026-08-18 12:21 UTCEG score recompute
  22. 2026-08-18 12:21 UTCVendor advisory
  23. 2026-08-18 07:26 UTCEG score recompute
  24. 2026-08-18 07:26 UTCVendor advisory
  25. 2026-08-18 07:03 UTCVendor advisory
  26. 2026-08-18 06:36 UTCEG score recompute
  27. 2026-08-18 06:36 UTCVendor advisory
  28. 2026-08-17 13:47 UTCEPSS rescore
  29. 2026-08-17 12:25 UTCEG score recompute
  30. 2026-08-17 12:25 UTCVendor advisory
  31. 2026-08-17 12:13 UTCEG score recompute
  32. 2026-08-17 12:13 UTCVendor advisory
  33. 2026-08-17 07:22 UTCEG score recompute
  34. 2026-08-17 07:22 UTCVendor advisory
  35. 2026-08-17 06:42 UTCEG score recompute
  36. 2026-08-17 06:42 UTCVendor advisory
  37. 2026-08-16 14:56 UTCEPSS rescore
  38. 2026-08-16 11:33 UTCEG score recompute
  39. 2026-08-16 11:33 UTCVendor advisory
  40. 2026-08-16 10:46 UTCEG score recompute
  41. 2026-08-16 10:46 UTCVendor advisory
  42. 2026-08-16 08:17 UTCEG score recompute
  43. 2026-08-16 08:17 UTCVendor advisory
  44. 2026-08-16 02:14 UTCEPSS rescore
  45. 2026-08-15 01:30 UTCEPSS rescore
  46. 2026-08-14 18:44 UTCVendor advisory
  47. 2026-08-14 05:27 UTCEG score recompute
  48. 2026-08-14 05:27 UTCVendor advisory
  49. 2026-08-13 22:00 UTCEPSS rescore
  50. 2026-08-13 13:39 UTCEG score recompute
  51. 2026-08-13 13:39 UTCVendor advisory
  52. 2026-08-13 12:29 UTCEG score recompute
  53. 2026-08-13 12:29 UTCVendor advisory
  54. 2026-08-13 10:52 UTCVendor advisory
  55. 2026-08-12 21:22 UTCEG score recompute
  56. 2026-08-12 21:22 UTCVendor advisory
  57. 2026-08-12 21:09 UTCEG score recompute
  58. 2026-08-12 21:09 UTCVendor advisory
  59. 2026-08-12 13:51 UTCEPSS rescore
  60. 2026-08-12 12:38 UTCEG score recompute
  61. 2026-08-12 12:38 UTCVendor advisory
  62. 2026-08-12 12:13 UTCEG score recompute
  63. 2026-08-12 12:13 UTCVendor advisory
  64. 2026-08-12 05:37 UTCEG score recompute
  65. 2026-08-12 05:37 UTCVendor advisory
  66. 2026-08-12 04:28 UTCEG score recompute
  67. 2026-08-12 04:28 UTCVendor advisory
  68. 2026-08-11 18:40 UTCEG score recompute
  69. 2026-08-11 03:15 UTCEG score recompute
  70. 2026-08-11 00:00 UTCEPSS rescore
  71. 2026-08-09 18:04 UTCEG score recompute
  72. 2026-08-09 13:46 UTCEPSS rescore
  73. 2026-08-09 04:57 UTCEG score recompute
  74. 2026-08-08 16:37 UTCEPSS rescore
  75. 2026-08-07 14:58 UTCEG score recompute

Related CVEs(same vendor + 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 August 25, 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 0% probability of exploitation in the next 30 days, which ranks it in the top 95.6% of all scored CVEs.
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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