FKIE_CVE-2026-9798

Vulnerability from fkie_nvd - Published: 2026-05-28 06:16 - Updated: 2026-10-26 12:10
Severity
4.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Summary
A flaw was found in Keycloak, an open-source identity and access management solution. When a user account is temporarily locked due to repeated failed login attempts, an attacker with valid client credentials can exploit the Client-Initiated Backchannel Authentication (CIBA) flow to bypass this brute-force protection. This allows continued authentication attempts and token issuance even when the account should be locked, potentially enabling further unauthorized access attempts.
References
secalert@redhat.comhttps://access.redhat.com/errata/RHSA-2026:50846
secalert@redhat.comhttps://access.redhat.com/errata/RHSA-2026:50847
secalert@redhat.comhttps://access.redhat.com/errata/RHSA-2026:50848
secalert@redhat.comhttps://access.redhat.com/errata/RHSA-2026:50849
secalert@redhat.comhttps://access.redhat.com/security/cve/CVE-2026-9798Mitigation, Vendor Advisory
secalert@redhat.comhttps://bugzilla.redhat.com/show_bug.cgi?id=2482470Issue Tracking, Vendor Advisory
Impacted products
Vendor Product Version
redhat build_of_keycloak -
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "defaultStatus": "affected",
          "packageName": "rhbk/keycloak-operator-bundle",
          "product": "Red Hat build of Keycloak 26.4",
          "vendor": "Red Hat",
          "versions": [
            {
              "lessThan": "*",
              "status": "unaffected",
              "version": "26.4.14-1",
              "versionType": "rpm"
            }
          ]
        },
        {
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "defaultStatus": "affected",
          "packageName": "rhbk/keycloak-rhel9",
          "product": "Red Hat build of Keycloak 26.4",
          "vendor": "Red Hat",
          "versions": [
            {
              "lessThan": "*",
              "status": "unaffected",
              "version": "26.4-22",
              "versionType": "rpm"
            }
          ]
        },
        {
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "defaultStatus": "affected",
          "packageName": "rhbk/keycloak-rhel9-operator",
          "product": "Red Hat build of Keycloak 26.4",
          "vendor": "Red Hat",
          "versions": [
            {
              "lessThan": "*",
              "status": "unaffected",
              "version": "26.4-22",
              "versionType": "rpm"
            }
          ]
        },
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "defaultStatus": "unaffected",
          "packageName": "rhbk/keycloak-rhel9",
          "product": "Red Hat build of Keycloak 26.4.14",
          "vendor": "Red Hat"
        },
        {
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.6::el9"
          ],
          "defaultStatus": "affected",
          "packageName": "rhbk/keycloak-operator-bundle",
          "product": "Red Hat build of Keycloak 26.6",
          "vendor": "Red Hat",
          "versions": [
            {
              "lessThan": "*",
              "status": "unaffected",
              "version": "26.6.5-1",
              "versionType": "rpm"
            }
          ]
        },
        {
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.6::el9"
          ],
          "defaultStatus": "affected",
          "packageName": "rhbk/keycloak-rhel9",
          "product": "Red Hat build of Keycloak 26.6",
          "vendor": "Red Hat",
          "versions": [
            {
              "lessThan": "*",
              "status": "unaffected",
              "version": "26.6-11",
              "versionType": "rpm"
            }
          ]
        },
        {
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.6::el9"
          ],
          "defaultStatus": "affected",
          "packageName": "rhbk/keycloak-rhel9-operator",
          "product": "Red Hat build of Keycloak 26.6",
          "vendor": "Red Hat",
          "versions": [
            {
              "lessThan": "*",
              "status": "unaffected",
              "version": "26.6-11",
              "versionType": "rpm"
            }
          ]
        },
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.6::el9"
          ],
          "defaultStatus": "unaffected",
          "product": "Red Hat build of Keycloak 26.6.5",
          "vendor": "Red Hat"
        }
      ],
      "source": "secalert@redhat.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:-:*:*:*",
              "matchCriteriaId": "E5C930CB-4EAD-497B-A44B-D880F2A1F85B",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A flaw was found in Keycloak, an open-source identity and access management solution. When a user account is temporarily locked due to repeated failed login attempts, an attacker with valid client credentials can exploit the Client-Initiated Backchannel Authentication (CIBA) flow to bypass this brute-force protection. This allows continued authentication attempts and token issuance even when the account should be locked, potentially enabling further unauthorized access attempts."
    },
    {
      "lang": "es",
      "value": "Se encontr\u00f3 una falla en Keycloak, una soluci\u00f3n de gesti\u00f3n de identidad y acceso de c\u00f3digo abierto. Cuando una cuenta de usuario se bloquea temporalmente debido a repetidos intentos fallidos de inicio de sesi\u00f3n, un atacante con credenciales de cliente v\u00e1lidas puede explotar el flujo de autenticaci\u00f3n de canal de retorno iniciado por el cliente (CIBA) para eludir esta protecci\u00f3n contra fuerza bruta. Esto permite intentos de autenticaci\u00f3n continuos y emisi\u00f3n de tokens incluso cuando la cuenta deber\u00eda estar bloqueada, lo que podr\u00eda permitir intentos adicionales de acceso no autorizado."
    }
  ],
  "id": "CVE-2026-9798",
  "lastModified": "2026-10-26T12:10:00.130",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 4.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 1.4,
        "source": "secalert@redhat.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-9798",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-05-29T18:29:49.249825Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-05-28T06:16:29.330",
  "references": [
    {
      "source": "secalert@redhat.com",
      "url": "https://access.redhat.com/errata/RHSA-2026:50846"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://access.redhat.com/errata/RHSA-2026:50847"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://access.redhat.com/errata/RHSA-2026:50848"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://access.redhat.com/errata/RHSA-2026:50849"
    },
    {
      "source": "secalert@redhat.com",
      "tags": [
        "Mitigation",
        "Vendor Advisory"
      ],
      "url": "https://access.redhat.com/security/cve/CVE-2026-9798"
    },
    {
      "source": "secalert@redhat.com",
      "tags": [
        "Issue Tracking",
        "Vendor Advisory"
      ],
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2482470"
    }
  ],
  "sourceIdentifier": "secalert@redhat.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-305"
        }
      ],
      "source": "secalert@redhat.com",
      "type": "Secondary"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON

Loading timeline…




    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.