CVE-2026-66795

CRITICALPre-NVD 9.99.9—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 75% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
9.9EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.9Exploit: None knownExposed: 0

A fix is available — apply it.

A flaw was found in the managedcluster-import-controller. The Certificate Signing Request (CSR) auto-approval logic improperly validates incoming CSRs, specifically by not inspecting the signer name or decoding the PEM-encoded x509 CSR. This vulnerability allows a privileged service account on a spoke cluster to submit a malicious CSR. Successful exploitation can lead to privilege escalation, enabling the attacker to obtain administrative credentials on the hub cluster.

CVSS v3
9.9
EG Score
9.9(medium)
EG Risk
45(Track)
EG Risk 45/100SSVC: 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
Severity99% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
25%
KEV
Not listed

Published

August 17, 2026

Last Modified

September 8, 2026

Advisory Details (8)

Auto-updated Sep 15, 2026
Patch available. Sources: redhat.
redhat

2507540 – (CVE-2026-66795) CVE-2026-66795 managedcluster-import-controller: CSR auto-approver does not validate certificate Subject or signerName (spoke→hub cluster-admin)

https://bugzilla.redhat.com/show_bug.cgi?id=2507540
redhat Patch Available

CVE-2026-66795 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-66795
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:59593
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:59579
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:59559
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:59558
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:59557
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:59556

Vendor Advisories for CVE-2026-66795(7)

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

Patch Availability(6)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatmulticluster-engine/managedcluster-import-controller-rhel9:17870783302026-08-25redhat
redhatmulticluster-engine/managedcluster-import-controller-rhel9:17865779152026-08-25redhat
redhatmulticluster-engine/managedcluster-import-controller-rhel9:17872607792026-08-25redhat
redhatmulticluster-engine/managedcluster-import-controller-rhel9:17870782722026-08-25redhat
redhatmulticluster-engine/managedcluster-import-controller-rhel9:17872590442026-08-25redhat
redhatmulticluster-engine/managedcluster-import-controller-rhel9:17870783072026-08-25redhat

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.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 90× in last 7d / 380× 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 405 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-66795?
CVE-2026-66795 is a critical vulnerability published on August 17, 2026. A flaw was found in the managedcluster-import-controller. The Certificate Signing Request (CSR) auto-approval logic improperly validates incoming CSRs, specifically by not inspecting the signer name or decoding the PEM-encoded x509 CSR. This vulnerability allows a privileged service account on a…
When was CVE-2026-66795 disclosed?
CVE-2026-66795 was first published in the National Vulnerability Database on August 17, 2026, with the most recent update on September 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66795 actively exploited?
CVE-2026-66795 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 75.1% of all scored CVEs.
What is the CVSS score of CVE-2026-66795?
CVE-2026-66795 has a CVSS v3 base score of 9.9 (NVD).
How do I remediate CVE-2026-66795?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66795, 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.

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