CVE-2026-29143 S/MIME Decryption Impersonation

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...

CVE-2026-29143

CVE-2026-29143 affects SEPPmail Secure Email Gateway prior to version 15.0.3. The issue is that the inner S/MIME-encrypted MIME entity is not properly authenticated, enabling an attacker to manipulate trusted headers. The root cause is insufficient verification of the inner message, with potentia...