Vulnerability in Apache Airflow
CVE-2026-34538
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.
EPSS: 0.007 (48.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Apache Airflow
- Apache Software Foundation Airflow — versions 3.0.0
Weakness classification (CWE)
References
- security@apache.org (patch, Issue Tracking, Broken Link)
- security@apache.org (vendor-advisory, Mailing List, Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-34538?
- CVE-2026-34538 is a medium-severity vulnerability in Apache Airflow, classified under Exposure of Resource to Wrong Sphere. CVSS score: 6.5/10. Published 2026-04-09.
- How severe is CVE-2026-34538?
- Medium severity. CVSS v3 base score is 6.5 out of 10.