SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to hide security tags from users by crafting a long subject.

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.

SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to bypass subject sanitization and forge security tags using Unicode lookalike characters.

SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to bypass subject sanitization and forge tags such as [signed OK].

SEPPmail Secure Email Gateway before version 15.0.1 improperly validates S/MIME certificates issued for email addresses containing whitespaces, allowing signature spoofing.

SEPPmail Secure Email Gateway before version 15.0.1 does not properly communicate PGP signature verification results, leaving users unable to detect forged emails.

SEPPmail Secure Email Gateway before version 15.0.1 does not properly verify that a PGP signature was generated by the expected key, allowing signature spoofing.