CVE-2026-41016

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.

Score

CVSS 3.1 5.9 Medium

Status

Analyzed - security@apache.org

Published

2026-04-30

Last modified

2026-10-26

Weaknesses

CWE-295

Affected products

• Airflow (Apache)
• Apache Airflow Providers Smtp (Apache Software Foundation)

References

• https://github.com/apache/airflow/pull/65346
• https://lists.apache.org/thread/gb202qy5r31bgdd3d51d7s5o1jh40kc4