CVE-2026-40861: Apache Airflow Symlink and Path Traversal Vulnerability
Summary
CVE-2026-40861: 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. Affects apache-airflow versions < 3.2.2. Fixed in 3.2.2. How to fix ↓
Also tracked for
- airflow · Bitnami
The same CVE-2026-40861 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.
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Background
Apache Airflow is an open-source platform designed to programmatically author, schedule, and monitor workflows. It allows users to define workflows as Directed Acyclic Graphs (DAGs) and provides a rich user interface to manage and visualize these workflows. However, certain configurations can expose Airflow to security vulnerabilities, particularly when worker log folders are shared with the API server.
Vulnerability Detail
A vulnerability exists in Apache Airflow where a DAG author can create a symlink in their task's log directory that points to an arbitrary file readable by the API server process. This can lead to a read-path attack, allowing sensitive files like '/etc/passwd' or 'airflow.cfg' to be accessed. Additionally, a task_id containing '..' sequences can be accepted by the Task SDK's KEY_REGEX, leading to a write-path attack that can overwrite arbitrary files. This vulnerability primarily affects deployments where the worker log folder is shared with the API server, posing a significant risk of data leakage or corruption.
How To Fix
Latest published version: 3.3.2 as of 22 Oct 2026
pip install --upgrade "apache-airflow==3.3.2"Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
3.2.2
This is the first release that contains the fix.
pip install --upgrade "apache-airflow==3.2.2"Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a defense-in-depth mitigation, it is recommended to deploy the worker and API server with separate log volumes. This ensures that worker-controlled paths cannot reach the API server's filesystem, reducing the risk of exploitation.
Conclusion
In summary, CVE-2026-40861 is a significant vulnerability in Apache Airflow that can lead to unauthorized file access and overwriting. Users are strongly advised to upgrade to version 3.2.2 or later and implement best practices such as separating log volumes to enhance security.
See every vulnerability recorded for apache-airflow →
FAQ
CVE-2026-40861 is a vulnerability in Apache Airflow that allows a DAG author to create symlinks or use path traversal techniques to access or overwrite arbitrary files.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without requiring any signup.
If upgrading is not possible, ensure that your worker and API server are deployed with separate log volumes to mitigate the risk of this vulnerability.
The potential impacts include unauthorized access to sensitive files and the ability to overwrite critical files, which can lead to data loss or corruption.
The CVSS score of this vulnerability is 6.5, indicating a moderate level of severity.
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