CVE-2026-40861 PUBLISHED

Apache Airflow: Arbitrary File Read via Log Symlink following in FileTaskHandler

Assigner: apache
Reserved: 15.04.2026 Published: 01.06.2026 Updated: 01.06.2026

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.

Product Status

Vendor Apache Software Foundation
Product Apache Airflow
Versions Default: unaffected
  • affected from 0 to 3.2.2 (excl.)

Credits

  • Silas Boch finder
  • Lakshmikanthan K (letchupkt) finder
  • Jarek Potiuk remediation developer

References

Problem Types

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