CVE-2026-29137: Seppmail Secure Email Gateway

Medium severity, CVSS 5.3. EPSS: 0.3% chance of exploitation in the next 30 days.

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

Affected products

• Seppmail Secure Email Gateway: before 15.0.3 (fixed in 15.0.3)

Published 2026-04-02. Last modified 2026-06-17.