Description
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 products
apache: airflow
References2
- lists.apache.org/thread/gb202qy5r31bgdd3d51d7s5o1jh40kc4 Mailing ListVendor Advisory
- github.com/apache/airflow/pull/65346 Issue TrackingPatch
Metrics
- CVSS 3.1
-
5.9
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - EPSS — exploit probability
- 0% percentile: 19 · as of 13 November 2026
- CWE
- CWE-295
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