CVE-2026-2748CWE-295

S/MIME Certificate Subject Whitespace

High · published March 4, 2026

CVSS v4.0
7.8
EPSS
0%
Percentile
8.9
In the wild
Unconfirmed
What it is

SEPPmail Secure Email Gateway before version 15.0.1 improperly validates S/MIME certificates issued for email addresses containing whitespaces, allowing signature spoofing.

The record
Technical detail
CVSS v4.0
7.8 · HIGH
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
EPSS
0.00197 · 8.9th percentile
Weakness
CWE-295 · Improper Certificate Validation
Published
2026-03-04T08:48Z
EPSS history
Timeline
  • 04 MAR 08:48Z
    S/MIME Certificate Subject Whitespace
    cvelistv5