CVE-2026-34538: Apache Airflow: Authorization bypass in DagRun wait endpoint (XCom exposure)

[Rahul Vats <rahulvats () apache org>]

Severity: low 

Affected versions:

- Apache Airflow (apache-airflow) 3.0.0 before 3.2.0

Description:

Apache Airflow versions 3.0.0 through 3.1.8 DagRun wait endpoint returns XCom result values even to users who only have 
DAG Run read permissions, such as the Viewer role.This behavior conflicts with the FAB RBAC model, which treats XCom as 
a separate protected resource, and with the security model documentation that defines the Viewer role as read-only.

Airflow uses the FAB Auth Manager to manage access control on a per-resource basis. The Viewer role is intended to be 
read-only by default, and the security model documentation defines Viewer users as those who can inspect DAGs without 
accessing sensitive execution results.

Users are recommended to upgrade to Apache Airflow 3.2.0 which resolves this issue.

Credit:

selen (finder)
Kevin Yang (remediation developer)

References:

https://github.com/apache/airflow/pull/64415
https://airflow.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-34538