Vulnerability-Lookup

CVE-2026-73266 (GCVE-0-2026-73266)

Vulnerability from cvelistv5 – Published: 2026-08-13 16:36 – Updated: 2026-08-18 01:25

Title

Clusterclaims-controller: clusterclaims-controller: tenant-controlled clusterclaim labels propagated to managedcluster enabling cross-tenant managedclusterset join

Summary

A flaw was found in the clusterclaims-controller component of Multicluster Engine (MCE). An authenticated tenant can exploit this vulnerability by manipulating ClusterClaim labels. This allows the tenant to force a cluster to join a ManagedClusterSet belonging to another tenant. Such unauthorized access could enable the injection of policies and workloads into other tenants' clusters.

Severity

7.1 (High)


                        
                          CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-18 01:25 UTC

CWE

CWE-441 - Unintended Proxy or Intermediary ('Confused Deputy')

Assigner

redhat redhat root

References

2 references

URL	Tags
https://access.redhat.com/security/cve/CVE-2026-73266	vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2514217	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

2026-08-11 00:00

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-73266",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-18T01:25:32.223923Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-18T01:25:47.546Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
          ],
          "defaultStatus": "affected",
          "packageName": "multicluster-engine/clusterclaims-controller-rhel9",
          "product": "Multicluster Engine for Kubernetes",
          "vendor": "Red Hat"
        }
      ],
      "datePublic": "2026-08-11T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "A flaw was found in the clusterclaims-controller component of Multicluster Engine (MCE). An authenticated tenant can exploit this vulnerability by manipulating ClusterClaim labels. This allows the tenant to force a cluster to join a ManagedClusterSet belonging to another tenant. Such unauthorized access could enable the injection of policies and workloads into other tenants\u0027 clusters."
        }
      ],
      "metrics": [
        {
          "other": {
            "content": {
              "namespace": "https://access.redhat.com/security/updates/classification/",
              "value": "Important"
            },
            "type": "Red Hat severity rating"
          }
        },
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-441",
              "description": "Unintended Proxy or Intermediary (\u0027Confused Deputy\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-13T16:36:45.097Z",
        "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "shortName": "redhat"
      },
      "references": [
        {
          "tags": [
            "vdb-entry",
            "x_refsource_REDHAT"
          ],
          "url": "https://access.redhat.com/security/cve/CVE-2026-73266"
        },
        {
          "name": "RHBZ#2514217",
          "tags": [
            "issue-tracking",
            "x_refsource_REDHAT"
          ],
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2514217"
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-08-10T00:00:00.000Z",
          "value": "Reported to Red Hat."
        },
        {
          "lang": "en",
          "time": "2026-08-11T00:00:00.000Z",
          "value": "Made public."
        }
      ],
      "title": "Clusterclaims-controller: clusterclaims-controller: tenant-controlled clusterclaim labels propagated to managedcluster enabling cross-tenant managedclusterset join",
      "workarounds": [
        {
          "lang": "en",
          "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability."
        }
      ],
      "x_generator": {
        "engine": "cvelib 1.8.0"
      },
      "x_redhatCweChain": "CWE-441: Unintended Proxy or Intermediary (\u0027Confused Deputy\u0027)"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
    "assignerShortName": "redhat",
    "cveId": "CVE-2026-73266",
    "datePublished": "2026-08-13T16:36:45.097Z",
    "dateReserved": "2026-08-11T17:22:38.645Z",
    "dateUpdated": "2026-08-18T01:25:47.546Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-73266",
      "date": "2026-08-18",
      "epss": "0.0016",
      "percentile": "0.05667"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-73266\",\"sourceIdentifier\":\"secalert@redhat.com\",\"published\":\"2026-08-13T17:17:35.713\",\"lastModified\":\"2026-08-18T02:17:28.680\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"A flaw was found in the clusterclaims-controller component of Multicluster Engine (MCE). An authenticated tenant can exploit this vulnerability by manipulating ClusterClaim labels. This allows the tenant to force a cluster to join a ManagedClusterSet belonging to another tenant. Such unauthorized access could enable the injection of policies and workloads into other tenants\u0027 clusters.\"}],\"affected\":[{\"source\":\"secalert@redhat.com\",\"affectedData\":[{\"vendor\":\"Red Hat\",\"product\":\"Multicluster Engine for Kubernetes\",\"defaultStatus\":\"affected\",\"collectionURL\":\"https://access.redhat.com/downloads/content/package-browser/\",\"packageName\":\"multicluster-engine/clusterclaims-controller-rhel9\",\"cpes\":[\"cpe:/a:redhat:multicluster_engine\"]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"secalert@redhat.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N\",\"baseScore\":7.1,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":1.8,\"impactScore\":4.7}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-08-18T01:25:32.223923Z\",\"id\":\"CVE-2026-73266\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"secalert@redhat.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-441\"}]}],\"references\":[{\"url\":\"https://access.redhat.com/security/cve/CVE-2026-73266\",\"source\":\"secalert@redhat.com\"},{\"url\":\"https://bugzilla.redhat.com/show_bug.cgi?id=2514217\",\"source\":\"secalert@redhat.com\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-08-13T17:10:58+00:00",
      "cve": "CVE-2026-73266",
      "id": "CVE-2026-73266",
      "initial_release_date": "2026-08-11T00:00:00+00:00",
      "product_status:known_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "clusterclaims-controller: clusterclaims-controller: tenant-controlled ClusterClaim labels propagated to ManagedCluster enabling cross-tenant ManagedClusterSet join",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-73266.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-73266\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-08-18T01:25:32.223923Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-08-18T01:25:38.586Z\"}}], \"cna\": {\"title\": \"Clusterclaims-controller: clusterclaims-controller: tenant-controlled clusterclaim labels propagated to managedcluster enabling cross-tenant managedclusterset join\", \"metrics\": [{\"other\": {\"type\": \"Red Hat severity rating\", \"content\": {\"value\": \"Important\", \"namespace\": \"https://access.redhat.com/security/updates/classification/\"}}}, {\"format\": \"CVSS\", \"cvssV3_1\": {\"scope\": \"CHANGED\", \"version\": \"3.1\", \"baseScore\": 7.1, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N\", \"integrityImpact\": \"LOW\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"HIGH\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"LOW\", \"confidentialityImpact\": \"HIGH\"}}], \"affected\": [{\"cpes\": [\"cpe:/a:redhat:multicluster_engine\"], \"vendor\": \"Red Hat\", \"product\": \"Multicluster Engine for Kubernetes\", \"packageName\": \"multicluster-engine/clusterclaims-controller-rhel9\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}], \"timeline\": [{\"lang\": \"en\", \"time\": \"2026-08-10T00:00:00.000Z\", \"value\": \"Reported to Red Hat.\"}, {\"lang\": \"en\", \"time\": \"2026-08-11T00:00:00.000Z\", \"value\": \"Made public.\"}], \"datePublic\": \"2026-08-11T00:00:00.000Z\", \"references\": [{\"url\": \"https://access.redhat.com/security/cve/CVE-2026-73266\", \"tags\": [\"vdb-entry\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://bugzilla.redhat.com/show_bug.cgi?id=2514217\", \"name\": \"RHBZ#2514217\", \"tags\": [\"issue-tracking\", \"x_refsource_REDHAT\"]}], \"workarounds\": [{\"lang\": \"en\", \"value\": \"Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.\"}], \"x_generator\": {\"engine\": \"cvelib 1.8.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"A flaw was found in the clusterclaims-controller component of Multicluster Engine (MCE). An authenticated tenant can exploit this vulnerability by manipulating ClusterClaim labels. This allows the tenant to force a cluster to join a ManagedClusterSet belonging to another tenant. Such unauthorized access could enable the injection of policies and workloads into other tenants\u0027 clusters.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-441\", \"description\": \"Unintended Proxy or Intermediary (\u0027Confused Deputy\u0027)\"}]}], \"providerMetadata\": {\"orgId\": \"53f830b8-0a3f-465b-8143-3b8a9948e749\", \"shortName\": \"redhat\", \"dateUpdated\": \"2026-08-13T16:36:45.097Z\"}, \"x_redhatCweChain\": \"CWE-441: Unintended Proxy or Intermediary (\u0027Confused Deputy\u0027)\"}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-73266\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-08-18T01:25:47.546Z\", \"dateReserved\": \"2026-08-11T17:22:38.645Z\", \"assignerOrgId\": \"53f830b8-0a3f-465b-8143-3b8a9948e749\", \"datePublished\": \"2026-08-13T16:36:45.097Z\", \"assignerShortName\": \"redhat\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}

FKIE_CVE-2026-73266

Vulnerability from fkie_nvd - Published: 2026-08-13 17:17 - Updated: 2026-08-18 02:17

Severity

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

Summary

References

	URL	Tags
	secalert@redhat.com	https://access.redhat.com/security/cve/CVE-2026-73266
	secalert@redhat.com	https://bugzilla.redhat.com/show_bug.cgi?id=2514217

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/clusterclaims-controller-rhel9",
          "product": "Multicluster Engine for Kubernetes",
          "vendor": "Red Hat"
        }
      ],
      "source": "secalert@redhat.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A flaw was found in the clusterclaims-controller component of Multicluster Engine (MCE). An authenticated tenant can exploit this vulnerability by manipulating ClusterClaim labels. This allows the tenant to force a cluster to join a ManagedClusterSet belonging to another tenant. Such unauthorized access could enable the injection of policies and workloads into other tenants\u0027 clusters."
    }
  ],
  "id": "CVE-2026-73266",
  "lastModified": "2026-08-18T02:17:28.680",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "LOW",
          "privilegesRequired": "LOW",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 4.7,
        "source": "secalert@redhat.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-73266",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-18T01:25:32.223923Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-13T17:17:35.713",
  "references": [
    {
      "source": "secalert@redhat.com",
      "url": "https://access.redhat.com/security/cve/CVE-2026-73266"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2514217"
    }
  ],
  "sourceIdentifier": "secalert@redhat.com",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-441"
        }
      ],
      "source": "secalert@redhat.com",
      "type": "Secondary"
    }
  ]
}

GHSA-XP42-V53J-R9GH

Vulnerability from github – Published: 2026-08-13 18:31 – Updated: 2026-08-13 18:31

Details

Severity

7.1 (High)


                  
                    CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-73266"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-441"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-13T17:17:35Z",
    "severity": "HIGH"
  },
  "details": "A flaw was found in the clusterclaims-controller component of Multicluster Engine (MCE). An authenticated tenant can exploit this vulnerability by manipulating ClusterClaim labels. This allows the tenant to force a cluster to join a ManagedClusterSet belonging to another tenant. Such unauthorized access could enable the injection of policies and workloads into other tenants\u0027 clusters.",
  "id": "GHSA-xp42-v53j-r9gh",
  "modified": "2026-08-13T18:31:41Z",
  "published": "2026-08-13T18:31:41Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-73266"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-73266"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2514217"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:L/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-2026-73266 (GCVE-0-2026-73266)

FKIE_CVE-2026-73266

GHSA-XP42-V53J-R9GH

Tags

Sightings

Nomenclature