CVE-2026-29143

EUVD-2026-18166
SEPPmail Secure Email Gateway before version 15.0.3 does not properly authenticate the inner message of S/MIME-encrypted MIME entities, allowing an attacker to control trusted headers.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
9.1 CRITICAL
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 18%
Affected Products (NVD)
VendorProductVersion
seppmailsecure_email_gateway
𝑥
< 15.0.3
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://downloads.seppmail.com/extrelnotes/150/ERN15.0.html#seppmail-vulnerability-disclosure-1503