CVE-2026-34538 Apache Airflow: Authorization bypass in DagRun wait endpoint (XCom exposure)
Users with Viewer role can access sensitive XCom results via the DagRun wait endpoint, bypassing intended read-only restrictions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-34538?
CVE-2026-34538 is a medium-severity missing authorization vulnerability in Apache Airflow, published on 9 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-668
Which versions are affected by CVE-2026-34538?
4 open source packages ship an affected version, including apache-airflow and airflow. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
apache-airflow PyPI | From 3.0.0 | 3.2.0 |
apache-airflow PyPI | From 3.0.0 | 3.2.0 |
apache-airflow PyPI | From 3.0.0 | 3.2.0 |
airflow Bitnami | From 3.0.0 | 3.2.0 |
Products include Apache Airflow.
How do I fix CVE-2026-34538?
Upgrade apache-airflow to 3.2.0 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-34538 being exploited?
There is no known exploitation of CVE-2026-34538 in the wild and no public exploit code.
Other vulnerabilities in Apache Airflow
- CVE-2020-13927 Apache Airflow's Experimental API Authentication Bypass
- CVE-2020-11978 Apache Airflow Command Injection
- CVE-2026-33264 Apache Airflow: DAG author RCE on webserver via unrestricted import_string() in BaseSerialization.deserialize()
- CVE-2023-25754 Apache Airflow: Privilege escalation using airflow logs
- CVE-2023-22884 Apache Airflow, Apache Airflow MySQL Provider: Arbitrary file read via MySQL provider in Apache Airflow
Sources
Also known as BIT-airflow-2026-34538, ECHO-1071-fe4c-2ff9, GHSA-r7vr-m4jw-r794, MINI-xhj8-q7cf-g9pr, PYSEC-2026-21.