CVE-2026-66794

CRITICALPre-NVD 9.39.3—
EchelonGraph scoreMEDIUM confidence

Score 9.3 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-19. A secondary CVSS source baseline 9.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
9.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 9.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

A flaw was found in the cluster-proxy-addon component of Multicluster Engine for Kubernetes. This vulnerability allows an unauthenticated attacker, who can access the user-facing route, to bypass authentication and authorization checks. By manipulating URL path segments, the attacker can proxy requests to arbitrary services across any managed cluster. This enables unauthorized access to internal services that would otherwise be protected, potentially leading to information disclosure or further compromise of the cluster environment.

CVSS v3
9.3
EG Score
9.3CRITICALmedium confidence
EG Risk
57
EG Risk 57/100CISA 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
Severity93% × 45%
Exploitation1% × 40%
Automatability100% × 15%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.6%
EPSS %ILE
47th
KEV
Not listed

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

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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 19, 2026

Last Modified

September 29, 2026

Advisory Details (8)

Auto-updated Oct 3, 2026
Patch available. Sources: redhat.
redhat

2507539 – (CVE-2026-66794) CVE-2026-66794 cluster-proxy-addon: cluster-proxy-addon: unauthenticated SSRF to arbitrary managed-cluster services via public Route

https://bugzilla.redhat.com/show_bug.cgi?id=2507539
redhat Patch Available

CVE-2026-66794 - 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-2026-66794
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-2026-66794(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/cluster-proxy-addon-rhel9:17871733612026-08-25redhat
redhatmulticluster-engine/cluster-proxy-addon-rhel9:17872753182026-08-25redhat
redhatmulticluster-engine/cluster-proxy-addon-rhel9:17872755192026-08-25redhat
redhatmulticluster-engine/cluster-proxy-addon-rhel9:17872749232026-08-25redhat
redhatmulticluster-engine/cluster-proxy-rhel9:17872767842026-08-25redhat
redhatmulticluster-engine/cluster-proxy-rhel9:17869833492026-08-25redhat

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 74× in last 7d / 360× 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 558 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-66794?
CVE-2026-66794 is a critical vulnerability published on August 19, 2026. A flaw was found in the cluster-proxy-addon component of Multicluster Engine for Kubernetes. This vulnerability allows an unauthenticated attacker, who can access the user-facing route, to bypass authentication and authorization checks. By manipulating URL path segments, the attacker can proxy…
When was CVE-2026-66794 disclosed?
CVE-2026-66794 was first published on August 19, 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-2026-66794 actively exploited?
CVE-2026-66794 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (47th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-66794?
CVE-2026-66794 has a CVSS base score of 9.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-66794?
A fix for CVE-2026-66794 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-66794 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-66794

Explore →

Is Your Infrastructure Affected by CVE-2026-66794?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs