Email Gateway Vulnerability in SEPPmail Affects Users' Security Visibility
CVE-2026-29137

5.3MEDIUM

Key Information:

Vendor

Seppmail

Status
Secure Email Gateway
Vendor
CVE Published:
2 April 2026

What is CVE-2026-29137?

A vulnerability exists in SEPPmail Secure Email Gateway versions before 15.0.3 that enables an attacker to manipulate email subjects. This manipulation allows the attacker to hide critical security tags from users, potentially leading to a lack of awareness regarding the security status of incoming emails. Addressing this vulnerability is crucial to maintaining the integrity and reliability of email communications.

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:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Andris Suter-Dörig
Matteo Scarlata
Kenny Paterson
.