Apache Airflow Providers SMTP: No certificate validation on SMTP STARTTLS connections in SMTP provider

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Summary

CVECVE-2026-41016
StatePUBLISHED
Assignerapache
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-04-30 10:16:01 UTC
Updated2026-04-30 10:16:01 UTC
DescriptionApache 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.

Risk And Classification

Problem Types: CWE-295 | CWE-295 CWE-295: Improper Certificate Validation

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Apache Software Foundation Apache Airflow Providers SMTP affected 2.0.0 3.0.0 semver Not specified

References

ReferenceSourceLinkTags
github.com/apache/airflow/pull/65346 [email protected] github.com
lists.apache.org/thread/gb202qy5r31bgdd3d51d7s5o1jh40kc4 [email protected] lists.apache.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Francis Bergin (@francisbergin) (en)

CNA: Jarek Potiuk (en)

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