CVE-2026-59243

The FAB auth manager's Azure AD OAuth login defaulted `verify_signature=False` when decoding the ID token, so an attacker able to present a forged or unsigned (`alg:none`) ID token to the OAuth callback could bypass authentication and log in as an arbitrary user, including one holding the Admin role (CWE-347). Deployments running the FAB auth manager with the Azure AD OAuth login path under its default configuration are affected; the Authentik path already defaulted to `True`. This issue affects `apache-airflow-providers-fab` before 3.7.3. Users are advised to upgrade to `apache-airflow-providers-fab` 3.7.3, which defaults `verify_signature=True`.

Score

CVSS 3.1 9.8 Critical

Status

Analyzed - security@apache.org

Published

2026-07-29

Last modified

2026-10-23

Weaknesses

CWE-347

Affected products

• Apache-airflow-providers-fab (Apache)
• Apache Airflow Fab Provider (Apache Software Foundation)

References

• https://github.com/apache/airflow/pull/69374
• https://lists.apache.org/thread/x4784l7z00tl3gw4tv2dmvoon77rxgpl
• http://www.openwall.com/lists/oss-security/2026/07/28/10