Vulnerability from bitnami_vulndb
Published
2026-08-25 11:42
Modified
2026-09-08 08:34
Summary
Keycloak: keycloak: access token disclosure and implicit flow bypass via forged client data
Details

A flaw was found in Keycloak. A low-privilege user, with knowledge of user credentials and client ID, can bypass a security control intended to disable the implicit flow in OpenID Connect (OIDC) clients. By manipulating client data during a session restart, an attacker can obtain an access token that should not be available. This vulnerability can also lead to the exposure of these access tokens in server logs, proxy logs, and HTTP Referrer headers, resulting in sensitive information disclosure.

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "keycloak",
        "purl": "pkg:bitnami/keycloak"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "26.4.0"
            },
            {
              "fixed": "26.4.12"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-7571"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:*",
      "cpe:2.3:a:keycloak:keycloak:*:*:*:*:*:*:*:*"
    ],
    "severity": "High"
  },
  "details": "A flaw was found in Keycloak. A low-privilege user, with knowledge of user credentials and client ID, can bypass a security control intended to disable the implicit flow in OpenID Connect (OIDC) clients. By manipulating client data during a session restart, an attacker can obtain an access token that should not be available. This vulnerability can also lead to the exposure of these access tokens in server logs, proxy logs, and HTTP Referrer headers, resulting in sensitive information disclosure.",
  "id": "BIT-keycloak-2026-7571",
  "modified": "2026-09-08T08:34:36.952Z",
  "published": "2026-08-25T11:42:36.952Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/errata/RHSA-2026:19596"
    },
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/errata/RHSA-2026:19597"
    },
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/security/cve/CVE-2026-7571"
    },
    {
      "type": "ADVISORY",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2464263"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-7571"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "Keycloak: keycloak: access token disclosure and implicit flow bypass via forged client data"
}



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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

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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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