CVE-2026-76187 Apache Software Foundation CVE debrief

Who should care

Administrators and users of Apache Airflow with Keycloak authentication, especially those with shared realms and confidential clients, should be aware of this vulnerability and take necessary actions to mitigate it. They should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance. They should also plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.

Why it matters

CVE-2026-76187 vulnerability in Apache Airflow Keycloak provider allows unauthenticated access to token endpoint, enabling Airflow login with unrelated application credentials, and requires urgent upgrade to version 0.10.0 or later.

• Potential unauthorized access to Airflow resources
• Possible elevation of privileges for attackers with valid credentials
• Need for urgent upgrade to patched version
• Verification of client authentication and authorization configurations

Technical summary

The unauthenticated token endpoint in Apache Airflow Keycloak provider accepts a client-credentials grant for any confidential client registered in the Keycloak realm, allowing Airflow login with credentials of an unrelated application sharing the realm. This vulnerability 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.

Defensive priority

Upgrade to version 0.10.0 or later of apache-airflow-providers-keycloak to restrict client authentication.

Recommended defensive actions

• Upgrade to version 0.10.0 or later of apache-airflow-providers-keycloak
• Restrict client authentication to only the configured client
• Monitor for potential exploitation attempts
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, its impact, and recommended actions. The vulnerability allows unauthenticated access to the token endpoint, enabling Airflow login with unrelated application credentials. The CVE record was published on 2026-09-16T10:16:52.910Z and has not been modified since then. The NVD entry provides additional information on the vulnerability and its impact.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.