CVE-2026-4740

Estado: ModificadaAlta (8.2)—

A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM). Improper validation of Kubernetes client certificate renewal allows a managed cluster administrator to forge a client certificate that can be approved by the OCM controller. This enables cross-cluster privilege escalation and may allow an attacker to gain control over other managed clusters, including the hub cluster.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
Puntuación base: 8.2

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.16%
Percentil entre todas las CVEs puntuadas: 5
Fecha de la puntuación: 5/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation85 %
Impacto principalT1078.001 Default Accountsstealth · persistence · privilege escalation · initial access80 %
Impacto secundarioT1021.006 Windows Remote Managementlateral movement70 %
Impacto secundarioT1098.003 Additional Cloud Rolespersistence · privilege escalation75 %

La improper validation de certificados permite a un administrador local forjar credenciales válidas (T1078.001) para autenticarse entre clusters, escalando privilegios hacia otros clusters incluyendo hub (T1068). Acceso local sin interacción del usuario (AV:L, UI:N, PR:H) con impacto crítico en conf

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Privileged Account Management Multi-factor Authentication User Account Management Threat Intelligence Program Password Policies Network Segmentation

Tecnologías afectadas (1)

Redhat — Advanced Cluster Management FOR Kubernetes

CWE

CWE-295
CWE-295

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-4740",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-4740",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-04-09T14:40:37.454585Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "secalert@redhat.com",
        "cvssData": {
          "scope": "CHANGED",
          "version": "3.1",
          "baseScore": 8.2,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "HIGH",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 6,
        "exploitabilityScore": 1.5
      },
      {
        "type": "Secondary",
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
        "cvssData": {
          "scope": "CHANGED",
          "version": "3.1",
          "baseScore": 8.2,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "HIGH",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 6,
        "exploitabilityScore": 1.5
      }
    ]
  },
  "affected": [
    {
      "source": "secalert@redhat.com",
      "affectedData": [
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine:2.10::el9"
          ],
          "vendor": "Red Hat",
          "product": "multicluster engine for Kubernetes 2.1",
          "versions": [
            {
              "status": "unaffected",
              "version": "1776881164",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "multicluster-engine/registration-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine:2.11::el9"
          ],
          "vendor": "Red Hat",
          "product": "multicluster engine for Kubernetes 2.11",
          "versions": [
            {
              "status": "unaffected",
              "version": "1777478390",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "multicluster-engine/registration-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine:2.6::el9"
          ],
          "vendor": "Red Hat",
          "product": "multicluster engine for Kubernetes 2.6",
          "versions": [
            {
              "status": "unaffected",
              "version": "1775977180",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "multicluster-engine/registration-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine:2.8::el9"
          ],
          "vendor": "Red Hat",
          "product": "multicluster engine for Kubernetes 2.8",
          "versions": [
            {
              "status": "unaffected",
              "version": "1775638726",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "multicluster-engine/registration-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine:2.9::el9"
          ],
          "vendor": "Red Hat",
          "product": "multicluster engine for Kubernetes 2.9",
          "versions": [
            {
              "status": "unaffected",
              "version": "1776445095",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "multicluster-engine/registration-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
          ],
          "vendor": "Red Hat",
          "product": "Multicluster Engine for Kubernetes",
          "packageName": "multicluster-engine/addon-manager-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unknown"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
          ],
          "vendor": "Red Hat",
          "product": "Multicluster Engine for Kubernetes",
          "packageName": "multicluster-engine/maestro-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unknown"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
          ],
          "vendor": "Red Hat",
          "product": "Multicluster Engine for Kubernetes",
          "packageName": "multicluster-engine/managedcluster-import-controller-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unknown"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
          ],
          "vendor": "Red Hat",
          "product": "Multicluster Engine for Kubernetes",
          "packageName": "multicluster-engine/placement-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unknown"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
          ],
          "vendor": "Red Hat",
          "product": "Multicluster Engine for Kubernetes",
          "packageName": "multicluster-engine/registration-operator-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unknown"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
          ],
          "vendor": "Red Hat",
          "product": "Multicluster Engine for Kubernetes",
          "packageName": "multicluster-engine/work-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unknown"
        }
      ]
    },
    {
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "affectedData": [
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine:2.10::el9"
          ],
          "vendor": "Red Hat",
          "product": "multicluster engine for Kubernetes 2.1",
          "versions": [
            {
              "status": "unaffected",
              "version": "1776881164",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "multicluster-engine/registration-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine:2.11::el9"
          ],
          "vendor": "Red Hat",
          "product": "multicluster engine for Kubernetes 2.11",
          "versions": [
            {
              "status": "unaffected",
              "version": "1777478390",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "multicluster-engine/registration-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine:2.6::el9"
          ],
          "vendor": "Red Hat",
          "product": "multicluster engine for Kubernetes 2.6",
          "versions": [
            {
              "status": "unaffected",
              "version": "1775977180",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "multicluster-engine/registration-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine:2.8::el9"
          ],
          "vendor": "Red Hat",
          "product": "multicluster engine for Kubernetes 2.8",
          "versions": [
            {
              "status": "unaffected",
              "version": "1775638726",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "multicluster-engine/registration-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine:2.9::el9"
          ],
          "vendor": "Red Hat",
          "product": "multicluster engine for Kubernetes 2.9",
          "versions": [
            {
              "status": "unaffected",
              "version": "1776445095",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "multicluster-engine/registration-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
          ],
          "vendor": "Red Hat",
          "product": "Multicluster Engine for Kubernetes",
          "packageName": "multicluster-engine/addon-manager-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unknown"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
          ],
          "vendor": "Red Hat",
          "product": "Multicluster Engine for Kubernetes",
          "packageName": "multicluster-engine/maestro-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unknown"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
          ],
          "vendor": "Red Hat",
          "product": "Multicluster Engine for Kubernetes",
          "packageName": "multicluster-engine/managedcluster-import-controller-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unknown"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
          ],
          "vendor": "Red Hat",
          "product": "Multicluster Engine for Kubernetes",
          "packageName": "multicluster-engine/placement-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unknown"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
          ],
          "vendor": "Red Hat",
          "product": "Multicluster Engine for Kubernetes",
          "packageName": "multicluster-engine/registration-operator-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unknown"
        },
        {
          "cpes": [
            "cpe:/a:redhat:multicluster_engine"
          ],
          "vendor": "Red Hat",
          "product": "Multicluster Engine for Kubernetes",
          "packageName": "multicluster-engine/work-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unknown"
        }
      ]
    }
  ],
  "published": "2026-04-07T15:17:46.797",
  "references": [
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:11414",
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:13542",
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:13853",
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:8218",
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:9848",
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://access.redhat.com/security/cve/CVE-2026-4740",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://blog.arfevrier.fr/open-cluster-management-cross-cluster-escape/",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450590",
      "tags": [
        "Issue Tracking",
        "Vendor Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:11414",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:13542",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:13853",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:8218",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:9848",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/security/cve/CVE-2026-4740",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450590",
      "tags": [
        "Issue Tracking",
        "Vendor Advisory"
      ],
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4740.json",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "secalert@redhat.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-295"
        }
      ]
    },
    {
      "type": "Secondary",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "description": [
        {
          "lang": "en",
          "value": "CWE-295"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM). Improper validation of Kubernetes client certificate renewal allows a managed cluster administrator to forge a client certificate that can be approved by the OCM controller. This enables cross-cluster privilege escalation and may allow an attacker to gain control over other managed clusters, including the hub cluster."
    }
  ],
  "lastModified": "2026-09-08T12:16:54.783",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:redhat:advanced_cluster_management_for_kubernetes:-:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "7301AD20-0188-463F-9386-9D878AD3A542"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "secalert@redhat.com"
}