CVE-2026-2603

Estado: AnalizadaAlta (8.1)—

A flaw was found in Keycloak. A remote attacker could bypass security controls by sending a valid SAML response from an external Identity Provider (IdP) to the Keycloak SAML endpoint for IdP-initiated broker logins. This allows the attacker to complete broker logins even when the SAML Identity Provider is disabled, leading to unauthorized authentication.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Puntuación base: 8.1

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.72%
Percentil entre todas las CVEs puntuadas: 52
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.

ExplotaciónT1210 Exploitation of Remote Serviceslateral movement85 %
Impacto principalT1078 Valid Accountsstealth · persistence · privilege escalation · initial access90 %
Impacto secundarioT1556 Modify Authentication Processdefense impairment · persistence · credential access75 %

Vector CVSS con AV:N, PR:L, sin UI:R indica explotación remota que requiere privilegios de red (T1210). El bypass de controles de autenticación SAML permite obtener acceso no autorizado (T1078) y manipular mecanismos de autenticación (T1556).

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 User Account Management Password Policies Multi-factor Authentication Application Developer Guidance Active Directory Configuration

Tecnologías afectadas (1)

Redhat — Build OF Keycloak

CWE

CWE-306
CWE-306

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-2603",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-2603",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-03-18T14:10:05.707703Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "secalert@redhat.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.1,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.2,
        "exploitabilityScore": 2.8
      },
      {
        "type": "Secondary",
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.1,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.2,
        "exploitabilityScore": 2.8
      }
    ]
  },
  "affected": [
    {
      "source": "secalert@redhat.com",
      "affectedData": [
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.2::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.2",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.2.14-1",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "rhbk/keycloak-operator-bundle",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.2::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.2",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.2-16",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "rhbk/keycloak-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.2::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.2",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.2-16",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "rhbk/keycloak-rhel9-operator",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.2::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.2.14",
          "packageName": "rhbk/keycloak-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.4",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.4.10-1",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "rhbk/keycloak-operator-bundle",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.4",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.4-12",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "rhbk/keycloak-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.4",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.4-12",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "rhbk/keycloak-rhel9-operator",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.4.10",
          "packageName": "rhbk/keycloak-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        }
      ]
    },
    {
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "affectedData": [
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.2::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.2",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.2.14-1",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "rhbk/keycloak-operator-bundle",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.2::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.2",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.2-16",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "rhbk/keycloak-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.2::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.2",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.2-16",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "rhbk/keycloak-rhel9-operator",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.2::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.2.14",
          "packageName": "rhbk/keycloak-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.4",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.4.10-1",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "rhbk/keycloak-operator-bundle",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.4",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.4-12",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "rhbk/keycloak-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.4",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.4-12",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "rhbk/keycloak-rhel9-operator",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.4.10",
          "packageName": "rhbk/keycloak-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-03-18T02:16:24.813",
  "references": [
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:3925",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:3926",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:3947",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:3948",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://access.redhat.com/security/cve/CVE-2026-2603",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2440300",
      "tags": [
        "Exploit",
        "Issue Tracking",
        "Vendor Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:3925",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:3926",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:3947",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:3948",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/security/cve/CVE-2026-2603",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2440300",
      "tags": [
        "Exploit",
        "Issue Tracking",
        "Vendor Advisory"
      ],
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2440300",
      "tags": [
        "Exploit",
        "Issue Tracking",
        "Vendor Advisory"
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    },
    {
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-2603.json",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "secalert@redhat.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-306"
        }
      ]
    },
    {
      "type": "Secondary",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "description": [
        {
          "lang": "en",
          "value": "CWE-306"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "A flaw was found in Keycloak. A remote attacker could bypass security controls by sending a valid SAML response from an external Identity Provider (IdP) to the Keycloak SAML endpoint for IdP-initiated broker logins. This allows the attacker to complete broker logins even when the SAML Identity Provider is disabled, leading to unauthorized authentication."
    },
    {
      "lang": "es",
      "value": "Se encontró una vulnerabilidad en Keycloak. Un atacante remoto podría eludir los controles de seguridad al enviar una respuesta SAML válida desde un Proveedor de Identidad (IdP) externo al punto final SAML de Keycloak para inicios de sesión de intermediario iniciados por el IdP. Esto permite al atacante completar inicios de sesión de intermediario incluso cuando el Proveedor de Identidad SAML está deshabilitado, lo que lleva a una autenticación no autorizada."
    }
  ],
  "lastModified": "2026-08-18T17:48:33.180",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "D39B54FB-C216-493F-A0D6-6F289959B3E9",
              "versionEndExcluding": "26.2.14",
              "versionStartIncluding": "26.2"
            },
            {
              "criteria": "cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "DFC39AF8-EEA9-4654-90AA-5456A0D48A6C",
              "versionEndExcluding": "26.4.10",
              "versionStartIncluding": "26.4"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "secalert@redhat.com"
}