Email Security Flaw in SEPPmail Secure Email Gateway from SEPPmail
CVE-2026-29138

6.3MEDIUM

Key Information:

Vendor

Seppmail

Status
Secure Email Gateway
Vendor
CVE Published:
2 April 2026

What is CVE-2026-29138?

A vulnerability in SEPPmail's Secure Email Gateway prior to version 15.0.3 enables attackers to exploit improperly handled PGP signatures. By using a specially crafted email address, malicious actors can impersonate legitimate users by claiming their PGP signatures. This raises significant security concerns for email integrity and user privacy, highlighting the need for immediate updates to protect against potential malicious activities.

Affected Version(s)

Secure Email Gateway 0 < 15.0.3

References

https://downloads.seppmail.com/extrelnotes/150/ERN15.0.ht...
release-notes

CVSS V4

Score:
6.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Andris Suter-Dörig
Matteo Scarlata
Kenny Paterson
.