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.
History

Fri, 01 May 2026 08:45:00 +0000

Type Values Removed Values Added
First Time appeared Apache
Apache airflow Providers Smtp
Vendors & Products Apache
Apache airflow Providers Smtp

Thu, 30 Apr 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 30 Apr 2026 09:45:00 +0000

Type Values Removed Values Added
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.
Title Apache Airflow Providers SMTP: No certificate validation on SMTP STARTTLS connections in SMTP provider
Weaknesses CWE-295
References

cve-icon MITRE

Status: PUBLISHED

Assigner: apache

Published: 2026-04-30T09:09:45.529Z

Updated: 2026-04-30T13:17:14.490Z

Reserved: 2026-04-16T02:38:58.158Z

Link: CVE-2026-41016

cve-icon Vulnrichment

Updated: 2026-04-30T13:17:11.334Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-04-30T10:16:01.930

Modified: 2026-04-30T15:09:49.123

Link: CVE-2026-41016

cve-icon Redhat

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