CVE-2026-40861

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.

PUBLISHED Reserved 2026-04-15 | Published 2026-06-01 | Updated 2026-06-02 | Assigner apache

Problem types

CWE-59: Improper Link Resolution Before File Access ('Link Following')

Product status

Credits

Silas Boch finder

Lakshmikanthan K (letchupkt) finder

Jarek Potiuk remediation developer

References

www.openwall.com/lists/oss-security/2026/05/31/1

github.com/apache/airflow/pull/65325 patch

lists.apache.org/thread/823334db2559xjlwt59gpzjz47thnscl vendor-advisory

cve.org (CVE-2026-40861)

nvd.nist.gov (CVE-2026-40861)

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