PT-2026-22895 · Seppmail · Seppmail Secure Email Gateway

Andris Suter-Dörig + 2 · Published 2026-03-04 · Updated 2026-03-04 · CVE-2026-2748

Positive Technologies (AI Summary)

CVSS v4.0

7.8

High

Base vector

AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:H/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 properly validate S/MIME certificates for email addresses that contain whitespaces, which can lead to signature spoofing.

Recommendations Update to version 15.0.1 or later.

Fix

Improper Certificate Validation

Weakness Enumeration

CWE-295

Related Identifiers

CVE-2026-2748

Affected Products

Seppmail Secure Email Gateway

References · 7

• https://nvd.nist.gov/vuln/detail/CVE-2026-2748 · Security Note
• https://downloads.seppmail.com/extrelnotes/150/ERN15.0.html#seppmail-vulnerability-disclosure · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2026-2748 · Vendor Advisory
• https://twitter.com/CVEarity/status/2029237724323168708 · Twitter Post
• https://t.me/CVEtracker/46302 · Telegram Post
• https://twitter.com/infoflowcloud/status/2029127417868976372 · Twitter Post
• https://twitter.com/CVEnew/status/2029125968091025512 · Twitter Post