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.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://github.com/apache/airflow/pull/65346 Issue Tracking, Patch
- https://lists.apache.org/thread/gb202qy5r31bgdd3d51d7s5o1jh40kc4 Mailing List, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 5.9 · apacheNVD modified 2026-10-26 21:10
Affected (CPE criteria) 1
cpe:2.3:a:apache:airflow:*:*:*:*:*:*:*:*
References 2
- https://github.com/apache/airflow/pull/65346 Issue Tracking, Patch
- https://lists.apache.org/thread/gb202qy5r31bgdd3d51d7s5o1jh40kc4 Mailing List, Vendor Advisory