CVE-2026-86466
Received
Received - Intake
OAuth Token Validation Bypass in Apache Airflow FAB Provider
Vulnerability report for CVE-2026-86466, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-16
Last updated on: 2026-09-16
Assigner: Apache Software Foundation
Description
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.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| apache | airflow_providers_fab | From 3.9.0 (inc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-346 | The product does not properly verify that the source of data or communication is valid. |
