PT-2026-29701 · Seppmail · Seppmail Secure Email Gateway

Andris Suter-Dörig + 2 · Published 2026-04-02 · Updated 2026-04-02 · CVE-2026-29137

Positive Technologies (AI Summary)

CVSS v3.1

5.3

Medium

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Name of the Vulnerable Software and Affected Versions SEPPmail Secure Email Gateway versions prior to 15.0.3

Description SEPPmail Secure Email Gateway versions prior to 15.0.3 are affected by an issue where an attacker can conceal security tags from users by creating a subject line of excessive length.

Recommendations Update SEPPmail Secure Email Gateway to version 15.0.3 or later.

Fix

RCE

Weakness Enumeration

CWE-20

Related Identifiers

CVE-2026-29137

Affected Products

Seppmail Secure Email Gateway

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-29137 · Security Note
• https://downloads.seppmail.com/extrelnotes/150/ERN15.0.html#seppmail-vulnerability-disclosure-1503 · Note
• https://twitter.com/CVEnew/status/2039647694524993763 · Twitter Post