Apache Airflow FAB Provider up to 3.8.0 OAuth Authentication improper authentication

Summaryinfo

A vulnerability was found in Apache Airflow FAB Provider up to 3.8.0 and classified as critical. This issue affects some unknown processing of the component OAuth Authentication. The manipulation results in improper authentication. This vulnerability is reported as CVE-2026-75156. The attack can be launched remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Apache Airflow FAB Provider up to 3.8.0. Affected is an unknown code of the component OAuth Authentication. The manipulation with an unknown input leads to a improper authentication vulnerability. CWE is classifying the issue as CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

Apache Airflow FAB provider versions 3.7.3 through 3.8.0 do not validate the issuer or audience of Azure AD `id_token`s during OAuth login. Deployments are affected only when the FAB auth manager is configured with Azure AD as an OAuth provider. Because the signing keys are fetched from Microsoft's **multi-tenant** JWKS endpoint, an `id_token` minted in *any* Azure tenant — including one the attacker creates — passes signature verification, and the username and role assignments are then read from that attacker-controlled token. Anyone able to register an Azure tenant can therefore authenticate to the Airflow UI with no prior access to the deployment. The fix for **CVE-2026-59243** was incomplete, and this advisory closes the remaining gap: that fix made the provider verify the `id_token` signature, but did not add issuer or audience checks. Operators who already applied the CVE-2026-59243 fix are **still affected and must upgrade again** — 3.7.3 is the release that shipped that fix, so every version containing it falls inside this affected range. Upgrade to apache-airflow-providers-fab `3.8.1` or later.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-75156 since 08/17/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 09/08/2026).

Upgrading to version 3.8.1 eliminates this vulnerability.

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Productinfo

Type

• Business Process Management Software

Vendor

• Apache

Name

• Airflow FAB Provider

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 3.5
• 3.6
• 3.7
• 3.8.0

License

• open-source

Website

• Vendor: https://www.apache.org/

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