CVE-2026-2748

S/MIME Certificate Subject Whitespace

Published Mar 4, 2026 CVSS 4.0 · 7.8 High EPSS < 1% KEV · Not listed
Description
SEPPmail Secure Email Gateway before version 15.0.1 improperly validates S/MIME certificates issued for email addresses containing whitespaces, allowing signature spoofing.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Seppmail seppmail
CPEs cpe:2.3:a:seppmail:seppmail:*:*:*:*:*:*:*:*
Vendors & Products Seppmail seppmail
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description SEPPmail Secure Email Gateway before version 15.0.1 improperly validates S/MIME certificates issued for email addresses containing whitespaces, allowing signature spoofing.
Title S/MIME Certificate Subject Whitespace
First Time appeared Seppmail
Seppmail seppmail Secure Email Gateway
Weaknesses CWE-295
CPEs cpe:2.3:a:seppmail:seppmail_secure_email_gateway:*:*:*:*:*:*:*:*
Vendors & Products Seppmail
Seppmail seppmail Secure Email Gateway
References
Metrics cvssV4_0

{'score': 7.8, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:H/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
NCSC.ch
Published
Updated
Mar 4, 2026, 4:55 PM
Reserved
Feb 19, 2026, 1:56 PM
Status
Analyzed
Published
Mar 4, 2026, 9:15 AM
Modified
Jun 17, 2026, 10:31 AM