Header Manipulation Vulnerability in SEPPmail Secure Email Gateway
CVE-2026-27443

8.2HIGH

Key Information:

Vendor

Seppmail

Status
Secure Email Gateway
Vendor
CVE Published:
4 March 2026

What is CVE-2026-27443?

The SEPPmail Secure Email Gateway prior to version 15.0.1 contains a vulnerability that fails to adequately sanitize headers originating from S/MIME protected MIME entities. This insufficiency can be exploited by attackers to manipulate trusted headers, raising significant security concerns for users relying on the integrity of email communications.

Affected Version(s)

Secure Email Gateway 0 < 15.0.1

References

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

CVSS V4

Score:
8.2
Severity:
HIGH
Confidentiality:
None
Integrity:
High
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
.