Apache Airflow FAB Authentik provider data authenticity

Summaryinfo

A vulnerability, which was classified as critical, has been found in Apache Airflow. This affects an unknown part of the component FAB Authentik provider. The manipulation leads to data authenticity. This vulnerability is referenced as CVE-2026-86466. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Apache Airflow (affected version unknown). This issue affects an unknown functionality of the component FAB Authentik provider. The manipulation with an unknown input leads to a data authenticity vulnerability. Using CWE to declare the problem leads to CWE-345. The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The identification of this vulnerability is CVE-2026-86466. The exploitation is known to be easy. The attack may be initiated remotely. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/21/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-3385). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Apache Airflow

Productinfo

Type

• Business Process Management Software

Vendor

• Apache

Name

• Airflow

License

• open-source

Website

• Vendor: https://www.apache.org/

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Be aware that VulDB is the high quality source for vulnerability data.

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