Vulnerability Description
A Dag author could either (a) create a symlink under their task's log directory pointing to an arbitrary file readable by the API server process (read-path attack — e.g. `/etc/passwd` or `airflow.cfg`) or (b) supply a `task_id` containing `..` sequences accepted by the Task SDK's `KEY_REGEX` (write-path attack), and in both cases the FileTaskHandler resolves the log path outside the configured `base_log_folder`, leaking or overwriting arbitrary files. Only affects deployments where the worker log folder is shared with the API server. Users are advised to upgrade to `apache-airflow` 3.2.2 or later. As a defense-in-depth mitigation, deploy the worker and API server with separate log volumes so that worker-controlled paths cannot reach the API server's filesystem.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Apache | Airflow | < 3.2.2 |
Related Weaknesses (CWE)
References
- https://github.com/apache/airflow/pull/65325Issue TrackingPatch
- https://lists.apache.org/thread/823334db2559xjlwt59gpzjz47thnsclMailing ListVendor Advisory
- http://www.openwall.com/lists/oss-security/2026/05/31/1Mailing ListThird Party Advisory
FAQ
What is CVE-2026-40861?
CVE-2026-40861 is a vulnerability with a CVSS score of 6.5 (MEDIUM). A Dag author could either (a) create a symlink under their task's log directory pointing to an arbitrary file readable by the API server process (read-path attack — e.g. `/etc/passwd` or `airflow.cfg`...
How severe is CVE-2026-40861?
CVE-2026-40861 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-40861?
Check the references section above for vendor advisories and patch information. Affected products include: Apache Airflow.