Apache Airflow Providers SMTP up to 2.x Self-Signed Certificate smtplib.SMTP.starttls certificate validation

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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3.6$0-$5k0.00

Summaryinfo

A vulnerability labeled as critical has been found in Apache Airflow Providers SMTP up to 2.x. This affects the function smtplib.SMTP.starttls of the component Self-Signed Certificate Handler. The manipulation results in certificate validation. This vulnerability was named CVE-2026-41016. The attack may be performed from remote. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Apache Airflow Providers SMTP up to 2.x. It has been classified as problematic. Affected is the function smtplib.SMTP.starttls of the component Self-Signed Certificate Handler. The manipulation with an unknown input leads to a certificate validation vulnerability. CWE is classifying the issue as CWE-295. The product does not validate, or incorrectly validates, a certificate. This is going to have an impact on integrity. CVE summarizes:

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.

The weakness was presented by Francis Bergin. The advisory is available at github.com. This vulnerability is traded as CVE-2026-41016 since 04/16/2026. The exploitability is told to be difficult. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 04/30/2026). This vulnerability is assigned to T1587.003 by the MITRE ATT&CK project.

Upgrading to version 3.0.0 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.7
VulDB Meta Temp Score: 3.6

VulDB Base Score: 3.7
VulDB Temp Score: 3.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Certificate validation
CWE: CWE-295 / CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Airflow Providers SMTP 3.0.0

Timelineinfo

04/16/2026 CVE reserved
04/30/2026 +14 days Advisory disclosed
04/30/2026 +0 days VulDB entry created
04/30/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: apache.org

Advisory: github.com
Researcher: Francis Bergin
Status: Confirmed

CVE: CVE-2026-41016 (🔒)
GCVE (CVE): GCVE-0-2026-41016
GCVE (VulDB): GCVE-100-360258

Entryinfo

Created: 04/30/2026 12:12
Changes: 04/30/2026 12:12 (58)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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