{"schema_version": "1.6.1", "id": "CVE-2026-41016", "summary": "No certificate validation on SMTP STARTTLS connections in SMTP provider", "details": "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.", "affected": [{"ranges": [{"type": "SEMVER", "events": [{"introduced": "2.0.0"}, {"fixed": "3.0.0"}]}]}], "references": [{"type": "WEB", "url": "https://github.com/apache/airflow/pull/65346"}, {"type": "WEB", "url": "https://lists.apache.org/thread/gb202qy5r31bgdd3d51d7s5o1jh40kc4"}]}