Improper Attachment Filename Handling in SEPPmail by SEPPmail AG
CVE-2026-8811

7.1HIGH

Key Information:

Vendor

Seppmail Ag

Status
Secure Email Gateway
Vendor
CVE Published:
18 June 2026

What is CVE-2026-8811?

SEPPmail versions prior to 15.0.5 are susceptible to an improper handling of attachment filenames, which occurs during encrypted PDF generation. This vulnerability could allow an attacker to perform a path traversal attack, potentially yielding unauthorized access to create files in unintended directories, including web-accessible locations. This could lead to significant security risks if exploited.

Affected Version(s)

Secure Email Gateway 0 < 15.0.5

References

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

CVSS V4

Score:
7.1
Severity:
HIGH
Confidentiality:
None
Integrity:
High
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Andris Suter-Dörig (ETH Zürich, Applied Crypto Group)
Olivier Becker (InfoGuard AG)
.