CVE-2026-29143
S/MIME Decryption Impersonation
Vexday Risk Score
21Low
SSVC decision (CISA)
Track
No exploitation signal → monitor
CVSS 7.8EPSS 0.3%KEV nãoPoC —Nuclei —Metasploit —Patch —
Lifecycle
02 Apr 2026Published on NVD
Recommendation: Monitor — no exploitation signal at the moment.
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.
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 GatewayWant to know if your infrastructure is exposed to this?
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