Vulnerability-Lookup

CVE-2026-66794 (GCVE-0-2026-66794)

Vulnerability from cvelistv5 – Published: 2026-08-19 17:30 – Updated: 2026-08-19 17:30

Title

Cluster-proxy-addon: cluster-proxy-addon: unauthenticated ssrf to arbitrary managed-cluster services via public route

Summary

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

CWE

CWE-918 - Server-Side Request Forgery (SSRF)

Assigner

redhat redhat root

References

2 references

URL	Tags
https://access.redhat.com/security/cve/CVE-2026-66794	vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2507539	issue-trackingx_refsource_REDHAT

Impacted products

1 product

Vendor	Product	Version	CPE status
Red Hat	Multicluster Engine for Kubernetes	cpe:/a:redhat:multicluster_engine

Date Public

2026-08-19 14:00

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
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          "packageName": "multicluster-engine/cluster-proxy-addon-rhel9",
          "product": "Multicluster Engine for Kubernetes",
          "vendor": "Red Hat"
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        }
      ],
      "metrics": [
        {
          "other": {
            "content": {
              "namespace": "https://access.redhat.com/security/updates/classification/",
              "value": "Important"
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            "type": "Red Hat severity rating"
          }
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          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 9.3,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "NONE",
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          "descriptions": [
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            }
          ]
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      "providerMetadata": {
        "dateUpdated": "2026-08-19T17:30:07.984Z",
        "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "shortName": "redhat"
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          "tags": [
            "vdb-entry",
            "x_refsource_REDHAT"
          ],
          "url": "https://access.redhat.com/security/cve/CVE-2026-66794"
        },
        {
          "name": "RHBZ#2507539",
          "tags": [
            "issue-tracking",
            "x_refsource_REDHAT"
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          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2507539"
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          "lang": "en",
          "time": "2026-07-27T00:00:00.000Z",
          "value": "Reported to Red Hat."
        },
        {
          "lang": "en",
          "time": "2026-08-19T14:00:00.000Z",
          "value": "Made public."
        }
      ],
      "title": "Cluster-proxy-addon: cluster-proxy-addon: unauthenticated ssrf to arbitrary managed-cluster services via public route",
      "workarounds": [
        {
          "lang": "en",
          "value": "To mitigate this issue, restrict network access to the user-facing Route of the `cluster-proxy-addon` to trusted networks only. Implement firewall rules to limit inbound connections to the Route\u0027s exposed port, ensuring only authorized sources can reach it. This reduces the attack surface by preventing unauthenticated external access to the vulnerable proxy."
        }
      ],
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        "engine": "cvelib 1.8.0"
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  "cveMetadata": {
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    "assignerShortName": "redhat",
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    "datePublished": "2026-08-19T17:30:07.984Z",
    "dateReserved": "2026-07-27T17:51:24.886Z",
    "dateUpdated": "2026-08-19T17:30:07.984Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
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      "current_release_date": "2026-08-19T18:09:43+00:00",
      "cve": "CVE-2026-66794",
      "id": "CVE-2026-66794",
      "initial_release_date": "2026-08-19T14:00:00+00:00",
      "product_status:known_affected": "2",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "cluster-proxy-addon: cluster-proxy-addon: unauthenticated SSRF to arbitrary managed-cluster services via public Route",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-66794.json",
      "version": "3"
    }
  }
}

FKIE_CVE-2026-66794

Vulnerability from fkie_nvd - Published: 2026-08-19 18:17 - Updated: 2026-08-19 18:17

Severity

9.3 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N

Summary

References

	URL	Tags
	secalert@redhat.com	https://access.redhat.com/security/cve/CVE-2026-66794
	secalert@redhat.com	https://bugzilla.redhat.com/show_bug.cgi?id=2507539

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
          ],
          "defaultStatus": "affected",
          "packageName": "multicluster-engine/cluster-proxy-addon-rhel9",
          "product": "Multicluster Engine for Kubernetes",
          "vendor": "Red Hat"
        },
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
          ],
          "defaultStatus": "affected",
          "packageName": "multicluster-engine/cluster-proxy-rhel9",
          "product": "Multicluster Engine for Kubernetes",
          "vendor": "Red Hat"
        }
      ],
      "source": "secalert@redhat.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
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      "lang": "en",
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    }
  ],
  "id": "CVE-2026-66794",
  "lastModified": "2026-08-19T18:17:16.547",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 9.3,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N",
          "version": "3.1"
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        "exploitabilityScore": 3.9,
        "impactScore": 4.7,
        "source": "secalert@redhat.com",
        "type": "Primary"
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  "published": "2026-08-19T18:17:16.547",
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      "url": "https://access.redhat.com/security/cve/CVE-2026-66794"
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      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2507539"
    }
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  "vulnStatus": "Received",
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      "type": "Primary"
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}

GHSA-9855-9CCH-X8MW

Vulnerability from github – Published: 2026-08-19 18:32 – Updated: 2026-08-19 18:32

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

Show details on source website

JSON

To clipboard

{
  "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": "2026-08-19T18:32:53Z",
  "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/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"
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

CVE-2026-66794 (GCVE-0-2026-66794)

FKIE_CVE-2026-66794

GHSA-9855-9CCH-X8MW

Tags

Sightings

Nomenclature