Seppmail
CVE-2026-2748
MEDIUM
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
2DescriptionCVE.org
SEPPmail Secure Email Gateway before version 15.0.1 improperly validates S/MIME certificates issued for email addresses containing whitespaces, allowing signature spoofing.
AnalysisAI
SEPPmail Secure Email Gateway versions before 15.0.1 fail to properly validate S/MIME certificates with whitespace characters in email addresses, enabling attackers to forge digital signatures and impersonate legitimate senders. This integrity bypass affects organizations relying on SEPPmail for secure email validation and could undermine trust in digitally signed communications. No patch is currently available for affected installations.
Technical ContextAI
Classified as CWE-295 (Improper Certificate Validation). Affects Seppmail. SEPPmail Secure Email Gateway before version 15.0.1 improperly validates S/MIME certificates issued for email addresses containing whitespaces, allowing signature spoofing.
RemediationAI
Monitor vendor advisories for a patch. Restrict network access to the affected service where possible.
Remote code execution in SeppMail secure email gateway versions 15.0.2.1 and earlier allows unauthenticated attackers to
Command injection in SEPPmail Secure Email Gateway before 15.0.1 via PDF encryption password.
SEPPmail Secure Email Gateway before version 15.0.3 allows attackers to bypass subject sanitization and forge security t
SEPPmail Secure Email Gateway before version 15.0.3 fails to properly authenticate inner messages within S/MIME-encrypte
Account takeover in SEPPmail Secure Email Gateway versions before 15.0.3 allows unauthenticated attackers to reset victi
SEPPmail Secure Email Gateway before version 15.0.3 allows remote attackers to bypass subject line sanitization controls
SEPPmail Secure Email Gateway before version 15.0.3 allows remote attackers to inject malicious certificates into S/MIME
SEPPmail Secure Email Gateway versions before 15.0.1 fail to properly validate S/MIME message headers, enabling attacker
Improper filename validation in SEPPmail Secure Email Gateway's GINA web interface (versions before 15.0.1) enables unau
SEPPmail Secure Email Gateway versions prior to 15.0.1 fail to properly isolate decrypted PGP message content from surro
SEPPmail Secure Email Gateway versions before 15.0.1 misinterpret email addresses in message headers, enabling attackers
Session hijacking in SEPPmail Secure Email Gateway and SEPPmail Cloud before 15.0.4.2 lets an attacker who can observe t
Same weakness CWE-295 – Improper Certificate Validation
View allSame technique Authentication Bypass
View allShare
External POC / Exploit Code
Leaving vuln.today