PT-2026-22889 · Seppmail · Seppmail Secure Email Gateway

Andris Suter-Dörig + 2 · Published 2026-03-04 · Updated 2026-03-05 · CVE-2026-27443

Positive Technologies (AI Summary)

CVSS v4.0

8.2

High

Base vector

AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:N

Name of the Vulnerable Software and Affected Versions SEPPmail Secure Email Gateway versions prior to 15.0.1

Description The SEPPmail Secure Email Gateway does not correctly handle headers within S/MIME protected MIME entities. This allows an attacker to manipulate trusted headers. The issue involves improper sanitization of headers, potentially leading to control over trusted header values.

Recommendations Update to SEPPmail Secure Email Gateway version 15.0.1 or later.

Fix

RCE

Weakness Enumeration

CWE-20

Related Identifiers

CVE-2026-27443

Affected Products

Seppmail Secure Email Gateway

References · 9

• https://osv.dev/vulnerability/CVE-2026-27443 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-27443 · Security Note
• https://downloads.seppmail.com/extrelnotes/150/ERN15.0.html#seppmail-vulnerability-disclosure · Vendor Advisory
• https://t.me/cveNotify/154347 · Telegram Post
• https://twitter.com/VulmonFeeds/status/2029139246968115309 · Twitter Post
• https://twitter.com/CVEarity/status/2029240438348235041 · Twitter Post
• https://twitter.com/infoflowcloud/status/2029127502115770498 · Twitter Post
• https://t.me/CVEtracker/46296 · Telegram Post
• https://twitter.com/CVEnew/status/2029125973283569869 · Twitter Post