CVE-2026-29143CWE-20
S/MIME Decryption Impersonation
High · published April 2, 2026
What it is
SEPPmail Secure Email Gateway before version 15.0.3 does not properly authenticate the inner message of S/MIME-encrypted MIME entities, allowing an attacker to control trusted headers.
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
- 0.00427 · 35.9th percentile
- Weakness
- CWE-20 · Improper Input Validation
- Published
- 2026-04-02T08:49Z
EPSS history
Timeline