Vulnerability 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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Apache | Airflow | >= 2.0.0, < 3.0.0 |
Related Weaknesses (CWE)
References
- https://github.com/apache/airflow/pull/65346Issue TrackingPatch
- https://lists.apache.org/thread/gb202qy5r31bgdd3d51d7s5o1jh40kc4Mailing ListVendor Advisory
FAQ
What is CVE-2026-41016?
CVE-2026-41016 is a vulnerability with a CVSS score of 5.9 (MEDIUM). 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 t...
How severe is CVE-2026-41016?
CVE-2026-41016 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-41016?
Check the references section above for vendor advisories and patch information. Affected products include: Apache Airflow.