CVE-2026-41016

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

MEDIUM
5.9
CVSS Score
Published: April 30, 2026 at 09:09 AM UTC
Updated: October 26, 2026 at 09:10 PM UTC
2 products affected across 1 vendorAirflowApache Airflow Providers SMTP

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Severity
MEDIUM5.9
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

2.0.0 ≤ v < 3.0.0
2.0.0 ≤ v < 3.0.02.0.0
Affected range stops below 3.0.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

PatchIssue Tracking
Source: cverecord
https://github.com/apache/airflow/pull/65346
Vendor AdvisoryMailing List
Source: cverecord
https://lists.apache.org/thread/gb202qy5r31bgdd3d51d7s5o1jh40kc4

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.9MEDIUMCISA-ADP
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-295

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