EUVD-2026-18166
GHSA-q7v7-25qx-fcxf
7.8
CVSS 4.0
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CVSS 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/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
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
X
Lifecycle Timeline
3
EUVD ID Assigned
Apr 02, 2026 - 09:00 euvd
EUVD-2026-18166
Analysis Generated
Apr 02, 2026 - 09:00 vuln.today
CVE Published
Apr 02, 2026 - 08:49 nvd
HIGH 7.8
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.
Analysis
SEPPmail Secure Email Gateway before version 15.0.3 fails to properly authenticate inner messages within S/MIME-encrypted MIME entities, permitting attackers to manipulate trusted email headers and potentially forge message authenticity. This vulnerability affects the cryptographic validation layer of the gateway, enabling header injection attacks that could deceive users about message origin or content integrity. …
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Priority Score
39
Low
Medium
High
Critical
KEV: 0
EPSS: +0.1
CVSS: +39
POC: 0
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External POC / Exploit Code
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