Apache Airflow · Apache Airflow Fab Provider · CVE-2026-59243
**Name of the Vulnerable Software and Affected Versions**
apache-airflow-providers-fab versions prior to 3.7.3
**Description**
The FAB auth manager's Azure AD OAuth login process failed to verify the signature of the ID token by default, as the `verify signature` variable was set to `False`. This allows an attacker to bypass authentication and log in as any user, including those with Admin privileges, by providing a forged or unsigned ID token (using `alg:none`) to the OAuth callback.
**Recommendations**
Upgrade to version 3.7.3.