CVE-2026-41016
Apache Airflow Providers SMTP: No certificate validation on SMTP STARTTLS connections in SMTP provider
- State
- Published
- Severity
- 5.9 Medium
- Published
- Apr 30, 2026
- Updated
- Apr 30, 2026
- Reserved
- Apr 16, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 5.9 Medium | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N | CISA-ADP |
Weaknesses
- CWE-295 Improper Certificate Validation
Affected Products
| Product | Versions |
|---|---|
Apache Airflow Providers SMTPApache Software Foundation |
|
References
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