CVE & CISA-KEV CatalogNVD
CVE-2026-29143
CRITICAL9.1
CVSS v3
Description
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 v3 Vector
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Exploit Intelligence
0.25%probability of exploitation in 30 days
16thpercentile
Low risk: more likely to be exploited than 16% of all known CVEs.
References
Find and fix vulnerabilities across your fleet
TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
Start freeThis product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-16.