CVE-2026-76187

Apache Airflow Keycloak provider: Any realm client's credentials mint an Airflow session JWT

Published Sep 16, 2026 CVSS 3.1 · 9.8 Critical EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
First Time appeared Apache apache-airflow-providers-keycloak
CPEs cpe:2.3:a:apache:apache-airflow-providers-keycloak:*:*:*:*:*:*:*:*
Vendors & Products Apache apache-airflow-providers-keycloak
Type Values Removed Values Added
First Time appeared Apache
Apache airflow Keycloak Provider
Vendors & Products Apache
Apache airflow Keycloak Provider
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title Apache Airflow Keycloak provider: Any realm client's credentials mint an Airflow session JWT
Weaknesses CWE-287
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
apache
Published
Updated
Sep 17, 2026, 7:21 PM
Reserved
Aug 19, 2026, 10:41 AM
Status
Analyzed
Published
Sep 16, 2026, 10:16 AM
Modified
Sep 18, 2026, 2:27 PM