CVE-2026-29140
Received Received - Intake
Certificate Injection Vulnerability in SEPPmail Secure Email Gateway

Publication date: 2026-04-02

Last updated on: 2026-04-16

Assigner: Switzerland Government Common Vulnerability Program

Description
SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to cause attacker-controlled certificates to be used for future encryption to a victim by adding the certificates to S/MIME signatures.
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Meta Information
Published
2026-04-02
Last Modified
2026-04-16
Generated
2026-06-16
AI Q&A
2026-04-02
EPSS Evaluated
2026-06-15
NVD
CVE-2026-29140
EUVD
EUVD-2026-18160
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
seppmail secure_email_gateway to 15.0.3 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-295 The product does not validate, or incorrectly validates, a certificate.
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Impact Analysis

The vulnerability can lead to an attacker controlling the certificates used for encrypting emails to the victim. This could compromise the confidentiality of future encrypted communications, potentially allowing unauthorized access to sensitive information.

Executive Summary

This vulnerability affects SEPPmail Secure Email Gateway versions before 15.0.3. It allows an attacker to insert attacker-controlled certificates into S/MIME signatures. As a result, these malicious certificates can be used for future encryption directed at the victim.

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