GitHub Advisoryadvisory · PyPI

GHSA-x8mh-94wc-33gv apache-airflow-providers-smtp: No certificate validation on SMTP STARTTLS connections in SMTP provider

MEDIUM Published 2026-04-30 Modified 2026-05-22 Official page ↗
Aliases
CVE-2026-41016
Ecosystem
PyPI
Packages
apache-airflow-providers-smtp
Severity
Moderate
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Weaknesses
CWE-295
Reviewed
2026-05-22

Affected packages

• PyPI apache-airflow-providers-smtp: >= 2.0.0, < 3.0.0 → fixed in 3.0.0

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.

Related

Alias · CVE (1)

  • CVE-2026-41016 Apache Airflow's SMTP provider `SmtpHook` called Python's `smtplib.SMTP.starttls()` without an SSL context, so no certificate validation… vulnerability

Weakness · CWE (1)

  • CWE-295 Improper Certificate Validation weakness

References