CVE-2026-86466 Apache Airflow FAB provider: FAB Authentik provider: id_token issuer/audience not validated
Attackers can authenticate to Apache Airflow using valid tokens from other applications on the same Authentik instance due to missing issuer and audience validation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-86466?
CVE-2026-86466 is a high-severity authentication bypass vulnerability in Apache Airflow FAB provider, published on 16 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Apache Airflow FAB provider: the Authentik OAuth path in the FAB auth manager does not validate the issuer or audience claims of the id_token it accepts. An attacker holding a token that the same Authentik identity provider minted for a different client application can present it to Airflow and be authenticated as the user it names, because the audience claim is never checked. Affects deployments using the FAB auth manager with Authentik OAuth where the same Authentik instance also serves other applications; the attacker needs a valid token for any of those other applications, not for Airflow.
CVE-2026-75156 corrected the same missing validation on the Azure AD path in this file; the Authentik path was left unchanged and is fixed here. Deployments that applied the CVE-2026-75156 fix and use Authentik must also upgrade for this one.
Users of apache-airflow-providers-fab are recommended to upgrade to version 3.9.0 or later, which fixes the issue.
Weakness: CWE-346
Which versions are affected by CVE-2026-86466?
It affects 1 product.
Products include Apache Apache-Airflow-Providers-Fab.
How do I fix CVE-2026-86466?
Upgrade to a fixed version.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-86466 being exploited?
There is no known exploitation of CVE-2026-86466 in the wild and no public exploit code.
Other vulnerabilities in Apache Airflow FAB provider
- CVE-2026-82311 Security feature bypass in Apache Airflow FAB provider
- CVE-2026-59243 Auth bypass in Apache Airflow FAB provider
- CVE-2024-42447 Apache Airflow Providers FAB: FAB provider 1.2.1 and 1.2.0 did not let user to logout for Airflow
- CVE-2026-86462 Apache Airflow FAB provider: FAB Admin password PATCH does not invalidate database-backed sessions
- CVE-2026-75156 Auth bypass in Apache Airflow FAB provider
Sources
Also known as CLEANSTART-2026-RR24550, GHSA-6fx3-rxq6-j8w2.