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

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:

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

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

Link: CVE-2026-41016

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

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

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

Link: CVE-2026-41016

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.