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Critical · 9.8 Public exploit CVE-2026-59243 EUVD-2026-50216GHSA-q5r3-w69r-hrfw

Apache Airflow FAB provider: FAB auth manager: JWT signature verification disabled by default for Azure AD OAuth (`verify_signature` defaults to `False`)

Published Jul 29, 2026 · Updated Sep 16, 2026 · Assigned by apache

Vendor: Apache Software Foundation Product: Apache Airflow FAB provider

Description

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`.

Affected products

VendorProductAffectedFixed
Apache Software Foundation Apache Airflow FAB provider < 3.7.3 3.7.3

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 2 repositories

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

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References