CVE-2026-76187

CriticalCVSS 9.8

Published: 16/09/2026(UTC)Updated: 17/09/2026(UTC)Translated: 16/09/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.20%

9th percentile - higher than 9% of all known CVEs

Summary

In 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. The lack of an allowlist allows credentials of another application to be valid Airflow login credentials.

Risk Assessment

An attacker with credentials for any confidential client in the same realm can gain access to Airflow, potentially leading to unauthorized access to resources.

Recommendation

It is recommended to upgrade apache-airflow-providers-keycloak to version 0.10.0 or later, which accepts only the configured client for that grant.

Other vulnerabilities in Apache Airflow Keycloak provider

CVE-2026-76186Critical
In Apache Airflow Keycloak provider from version 3.3, the user identity is taken from the signed Airflow session token, but the Keycloak access and refresh tokens used for authorization come from separate, unauthenticated cookies and are never checked for consistency with the identity. This allows pairing foreign tokens with one's own session.

Original NVD description (English source)

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.