GHSA-9855-9CCH-X8MW

Vulnerability from github – Published: 2026-08-19 18:32 – Updated: 2026-09-05 15:30
VLAI
Details

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.

Severity
9.3 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
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{
  "affected": [],
  "aliases": [
    "CVE-2026-66794"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-19T18:17:16Z",
    "severity": "CRITICAL"
  },
  "details": "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.",
  "id": "GHSA-9855-9cch-x8mw",
  "modified": "2026-09-05T15:30:25Z",
  "published": "2026-08-19T18:32:53Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-66794"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:59556"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:59557"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:59558"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:59559"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:59579"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:59593"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-66794"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2507539"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}



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