FKIE_CVE-2026-76187

Vulnerability from fkie_nvd - Published: 2026-09-16 10:16 - Updated: 2026-09-17 20:18
Severity
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
Apache Airflow Keycloak provider: the unauthenticated token endpoint accepts a client-credentials grant for any confidential client registered in the Keycloak realm, not only the client configured for Airflow. No allowlist restricts which client ids may authenticate, so the credentials of an unrelated application that happens to share the realm are valid Airflow login credentials, and Airflow mints a signed session token for that application's service account. The endpoint also answers unauthenticated credential guesses against Keycloak under Airflow's identity. Affects deployments using the Keycloak auth manager whose realm is shared with other confidential clients. The attacker needs valid credentials for any one of those clients, not for Airflow. Resource authorization is still evaluated per subject, so the access gained is whatever that service account holds, plus any endpoint gated only on being authenticated. Users of apache-airflow-providers-keycloak are recommended to upgrade to version 0.10.0 or later, which accepts only the configured client on that grant.
References
security@apache.orghttps://github.com/apache/airflow/pull/72205
security@apache.orghttps://lists.apache.org/thread/5cqh5ojl3718ogb0q1dcd9vdr47z7gp3
security@apache.orghttps://lists.apache.org/thread/j1b9ddljxphqvoc41z7gthj4zh34vmlw?users@airflow.apache.org
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/09/15/9
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://pypi.python.org",
          "defaultStatus": "unaffected",
          "packageName": "apache-airflow-providers-keycloak",
          "packageURL": "pkg:pypi/apache-airflow-providers-keycloak",
          "product": "Apache Airflow Keycloak provider",
          "vendor": "Apache Software Foundation",
          "versions": [
            {
              "lessThan": "0.10.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "security@apache.org"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Apache Airflow Keycloak provider: the unauthenticated token endpoint accepts a client-credentials grant for any confidential client registered in the Keycloak realm, not only the client configured for Airflow. No allowlist restricts which client ids may authenticate, so the credentials of an unrelated application that happens to share the realm are valid Airflow login credentials, and Airflow mints a signed session token for that application\u0027s service account. The endpoint also answers unauthenticated credential guesses against Keycloak under Airflow\u0027s identity.\n\nAffects deployments using the Keycloak auth manager whose realm is shared with other confidential clients. The attacker needs valid credentials for any one of those clients, not for Airflow. Resource authorization is still evaluated per subject, so the access gained is whatever that service account holds, plus any endpoint gated only on being authenticated.\n\nUsers of apache-airflow-providers-keycloak are recommended to upgrade to version 0.10.0 or later, which accepts only the configured client on that grant."
    }
  ],
  "id": "CVE-2026-76187",
  "lastModified": "2026-09-17T20:18:15.083",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-76187",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-17T19:21:36.545412Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-16T10:16:52.910",
  "references": [
    {
      "source": "security@apache.org",
      "url": "https://github.com/apache/airflow/pull/72205"
    },
    {
      "source": "security@apache.org",
      "url": "https://lists.apache.org/thread/5cqh5ojl3718ogb0q1dcd9vdr47z7gp3"
    },
    {
      "source": "security@apache.org",
      "url": "https://lists.apache.org/thread/j1b9ddljxphqvoc41z7gthj4zh34vmlw?users@airflow.apache.org"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "http://www.openwall.com/lists/oss-security/2026/09/15/9"
    }
  ],
  "sourceIdentifier": "security@apache.org",
  "vulnStatus": "Undergoing Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-287"
        }
      ],
      "source": "security@apache.org",
      "type": "Secondary"
    }
  ]
}



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