Vulnerability in Seppmail Secure Email Gateway

CVE-2026-29140

SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to cause attacker-controlled certificates to be used for future encryption to a victim by adding the certificates to S/MIME signatures.

Vulnerability class: Improper Certificate Validation

EPSS: 0.000 (6.7th percentile) — read the EPSS interpretation.

Affected products

Seppmail Secure Email Gateway — versions 0

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

References

downloads.seppmail.com/extrelnotes/150/ERN15.0.html (release-notes)