CVE-2026-2748

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

CVSS v4.0

7.8 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1

5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS

0.12% chance of exploitation in the next 30 days, 2th percentile

Published

2026-03-04

Proof-of-concept exploits (1)

• lyducanh/atmnc

References

• CVE Record
• NVD entry

Related

• CVE-2025-15467
• CVE-2026-27476
• CVE-2026-27482
• CVE-2026-27475
• CVE-2026-27483
• CVE-2026-27474