CVE-2026-2748
S/MIME Certificate Validation Flaw in SEPPmail Enables Spoofing
Publication date: 2026-03-04
Last updated on: 2026-03-05
Assigner: Switzerland Government Common Vulnerability Program
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| seppmail | seppmail | to 15.0.1 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-295 | The product does not validate, or incorrectly validates, a certificate. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability affects SEPPmail Secure Email Gateway versions before 15.0.1. It occurs because the software improperly validates S/MIME certificates when the email addresses in those certificates contain whitespaces. This improper validation allows an attacker to spoof email signatures.
How can this vulnerability impact me? :
The vulnerability can allow attackers to spoof email signatures, potentially making malicious emails appear as if they come from trusted sources. This can lead to phishing attacks, unauthorized actions, or the spread of malware, undermining the trustworthiness of email communications.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know