CVE-2020-13927: Apache Airflow's Experimental API Authentication Bypass

Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2022-01-18. EPSS: 99.8% chance of exploitation in the next 30 days.

The previous default setting for Airflow's Experimental API was to allow all API requests without authentication, but this poses security risks to users who miss this fact. From Airflow 1.10.11 the default has been changed to deny all requests by default and is documented at https://airflow.apache.org/docs/1.10.11/security.html#api-authentication. Note this change fixes it for new installs but existing users need to change their config to default `[api]auth_backend = airflow.api.auth.backend.deny_all` as mentioned in the Updating Guide: https://github.com/apache/airflow/blob/1.10.11/UPDATING.md#experimental-api-will-deny-all-request-by-default

Affected products

• Apache Airflow: before 1.10.11 (fixed in 1.10.11)

Published 2020-11-10. Last modified 2026-06-17.