GHSA-Q6H7-XXP7-7429

Vulnerability from github – Published: 2026-05-28 06:31 – Updated: 2026-08-05 18:31
VLAI
Summary
Keycloak has an Authentication Bypass by Primary Weakness
Details

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.

Severity
4.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
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{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.keycloak:keycloak-services"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "26.4.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.keycloak:keycloak-services"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "26.5.0"
            },
            {
              "last_affected": "26.6.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-9798"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-305"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-01T21:26:22Z",
    "nvd_published_at": "2026-05-28T06:16:29Z",
    "severity": "MODERATE"
  },
  "details": "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.",
  "id": "GHSA-q6h7-xxp7-7429",
  "modified": "2026-08-05T18:31:21Z",
  "published": "2026-05-28T06:31:09Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-9798"
    },
    {
      "type": "WEB",
      "url": "https://github.com/keycloak/keycloak/issues/49432"
    },
    {
      "type": "WEB",
      "url": "https://github.com/keycloak/keycloak/pull/49791"
    },
    {
      "type": "WEB",
      "url": "https://github.com/keycloak/keycloak/pull/49903"
    },
    {
      "type": "WEB",
      "url": "https://github.com/keycloak/keycloak/pull/49905"
    },
    {
      "type": "WEB",
      "url": "https://github.com/keycloak/keycloak/commit/11c2695064cd93da1d333df3f69d4a4141e86c29"
    },
    {
      "type": "WEB",
      "url": "https://github.com/keycloak/keycloak/commit/2edc6b112e2dedce63062b89ab3c7ae542e0d9ac"
    },
    {
      "type": "WEB",
      "url": "https://github.com/keycloak/keycloak/commit/a11e3254efc16ae72ce5092b93b9f557a4ba43ae"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:50846"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:50847"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:50848"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:50849"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-9798"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2482470"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/keycloak/keycloak"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Keycloak has an Authentication Bypass by Primary Weakness"
}



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