Apache Airflow's EmailOperator and the underlying airflow.utils.email helpers established SMTP STARTTLS connections without verifying the remote certificate when the deployment used [email] smtpstarttls=True without [email] smtpssl. An attacker positioned between the worker and the configured SMTP server (network MITM — typical hostile-network attack-surface for environments where the SMTP relay sits outside the worker's trust boundary) could present a self-signed certificate, have the worker complete the STARTTLS handshake silently, and capture the SMTP AUTH credentials and message contents the worker forwarded.

This CVE covers the core apache-airflow side of the same root cause already covered for the SMTP provider by CVE-2026-41016 (published 2026-04-27, covering apache-airflow-providers-smtp). Users who already applied the SMTP-provider fix from CVE-2026-41016 should additionally upgrade apache-airflow to 3.2.2 or later to cover the core-side path through airflow.utils.email. Affects deployments configured with smtpstarttls=True and smtpssl=False where the SMTP relay is reachable across a less-trusted network segment than the worker.

Users are advised to upgrade to apache-airflow 3.2.2 or later.

Apache Airflow's SMTP provider SmtpHook called Python's smtplib.SMTP.starttls() without an SSL context, so no certificate validation was performed on the TLS upgrade. A man-in-the-middle between the Airflow worker and the SMTP server could present a self-signed certificate, complete the STARTTLS upgrade, and capture the SMTP credentials sent during the subsequent login() call. Users are advised to upgrade to the apache-airflow-providers-smtp version that contains the fix.

In Apache Airflow prior to 2.2.0. This CVE applies to a specific case where a User who has "cancreate" permissions on DAG Runs can create Dag Runs for dags that they don't have "edit" permissions for.

The "origin" parameter passed to some of the endpoints like '/trigger' was vulnerable to XSS exploit. This issue affects Apache Airflow versions <1.10.15 in 1.x series and affects 2.0.0 and 2.0.1 and 2.x series. This is the same as CVE-2020-13944 & CVE-2020-17515 but the implemented fix did not fix the issue completely. Update to Airflow 1.10.15 or 2.0.2. Please also update your Python version to the latest available PATCH releases of the installed MINOR versions, example update to Python 3.6.13 if you are on Python 3.6. (Those contain the fix for CVE-2021-23336 https://nvd.nist.gov/vuln/detail/CVE-2021-23336).

The lineage endpoint of the deprecated Experimental API was not protected by authentication in Airflow 2.0.0. This allowed unauthenticated users to hit that endpoint. This is low-severity issue as the attacker needs to be aware of certain parameters to pass to that endpoint and even after can just get some metadata about a DAG and a Task. This issue affects Apache Airflow 2.0.0.

Improper Access Control on Configurations Endpoint for the Stable API of Apache Airflow allows users with Viewer or User role to get Airflow Configurations including sensitive information even when [webserver] exposeconfig is set to False in airflow.cfg. This allowed a privilege escalation attack. This issue affects Apache Airflow 2.0.0.

The "origin" parameter passed to some of the endpoints like '/trigger' was vulnerable to XSS exploit. This issue affects Apache Airflow versions prior to 1.10.13. This is same as CVE-2020-13944 but the implemented fix in Airflow 1.10.13 did not fix the issue completely.

In Apache Airflow < 1.10.12, the "origin" parameter passed to some of the endpoints like '/trigger' was vulnerable to XSS exploit.