Vulnerability in Apache Airflow
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. `/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.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.008 (53.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 53.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.008 · change: +0.001
Affected products
- Apache Airflow
- Apache Software Foundation Airflow — versions 0
Weakness classification (CWE)
References
- github.com/apache/airflow/pull/65325 (Patch, patch, Issue Tracking)
- lists.apache.org/thread/823334db2559xjlwt59gpzjz47thnscl (vendor-advisory, Mailing List, Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-40861?
- CVE-2026-40861 is a medium-severity vulnerability in Apache Airflow, classified under Improper Link Resolution Before File Access. CVSS score: 6.5/10. Published 2026-06-01.
- How severe is CVE-2026-40861?
- Medium severity. CVSS v3 base score is 6.5 out of 10.