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: 0.5% (39th percentile of EPSS-scored CVEs). 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: 0.5%CVSS: 9.9Exploit: None knownExposed services: Not assessed

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
9.9CRITICALmedium confidence
EG Risk
45
EG Risk 45/100CISA SSVC

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%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.5%
EPSS %ILE
39th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 17, 2026

Last Modified

September 29, 2026

Advisory Details (8)

Auto-updated Sep 29, 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 / EcosystemFix (by version range) / 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 65× in last 7d / 348× 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 567 total refreshes for this CVE.

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

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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 on August 17, 2026, with the most recent update on September 29, 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 0.5% probability of exploitation in the next 30 days (39th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-66795?
CVE-2026-66795 has a CVSS base score of 9.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-66795?
A fix for CVE-2026-66795 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-66795 are linked in the Vendor Advisories panel on this page.

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