CVE-2026-2748

S/MIME Certificate Subject Whitespace

CVSS 7.8 HIGHEPSS 0.1%CWE-295

Vexday Risk Score

21Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 7.8EPSS 0.1%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

04 Mar 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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

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

Affected products

SEPPmail · Secure Email Gateway

Want to know if your infrastructure is exposed to this?

Talk to TrueHacking →

References

https://downloads.seppmail.com/extrelnotes/150/ERN15.0.html#seppmail-vulnerability-disclosure