CVE-2026-29140: high-severity vulnerability in SEPPmail Secure Email Gateway
S/MIME Signature Additional Certificate
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.7epss 0.1%
SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to cause attacker-controlled certificates to be used for future encryption to a victim by adding the certificates to S/MIME signatures.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:H/SI:N/SA:N
Affected products
SEPPmail · Secure Email GatewayRelated CVEs — SEPPmail Secure Email Gateway
In the same product, most dangerous first.
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