CVE-2026-29143

UNKNOWN 0.0

S/MIME Decryption Impersonation

CVSS Score

0.0

EPSS Score

0.1%

EPSS Percentile

25th

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.

CWE	CWE-20
Vendor	seppmail
Product	secure email gateway
Published	Apr 2, 2026
Last Updated	Apr 2, 2026

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Affected Versions

SEPPmail / Secure Email Gateway

0 < 15.0.3

References

NVD ↗ CVE.org ↗ EPSS Data ↗

downloads.seppmail.com: https://downloads.seppmail.com/extrelnotes/150/ERN15.0.html#seppmail-vulnerability-disclosure-1503

Credits

Andris Suter-Dörig Matteo Scarlata Kenny Paterson