« Volver al listado

CVE-2026-9803

Estado: ModificadaMedia (5.3)—

A flaw was found in Keycloak's ClientRegistrationAuth component. A remote unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with a malformed 'Authorization: Bearer' header to any client registration endpoint. This can lead to an ArrayIndexOutOfBoundsException, causing the server to return an HTTP 500 error and resulting in a Denial of Service (DoS) for the affected service.

CVSS

Probabilidad de explotación (EPSS)

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).

Tecnologías afectadas (1)

Redhat — Build OF Keycloak

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-9803",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-9803",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-05-28T13:09:44.442993Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "secalert@redhat.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.3,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "LOW",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 1.4,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "secalert@redhat.com",
      "affectedData": [
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.4",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.4.13-1",
              "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": "26.4-19",
              "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": "26.4-19",
              "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 26.4.13",
          "packageName": "rhbk/keycloak-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.6::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.6",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.6.3-3",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "rhbk/keycloak-operator-bundle",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.6::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.6",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.6-6",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "rhbk/keycloak-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.6::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.6",
          "versions": [
            {
              "status": "unaffected",
              "version": "26.6-6",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "rhbk/keycloak-rhel9-operator",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.6::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.6.3",
          "packageName": "rhbk/keycloak-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-05-28T06:16:29.750",
  "references": [
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:25097",
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:25098",
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:30049",
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:30050",
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://access.redhat.com/security/cve/CVE-2026-9803",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2482465",
      "tags": [
        "Issue Tracking",
        "Vendor Advisory"
      ],
      "source": "secalert@redhat.com"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "secalert@redhat.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "A flaw was found in Keycloak's ClientRegistrationAuth component. A remote unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with a malformed 'Authorization: Bearer' header to any client registration endpoint. This can lead to an ArrayIndexOutOfBoundsException, causing the server to return an HTTP 500 error and resulting in a Denial of Service (DoS) for the affected service."
    }
  ],
  "lastModified": "2026-06-26T08:16:35.157",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:-:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "E5C930CB-4EAD-497B-A44B-D880F2A1F85B"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "secalert@redhat.com"
}