CVE-2026-27443: high-severity vulnerability in SEPPmail Secure Email Gateway
S/MIME Decryption Tag Sanitization Bypass
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 8.2epss 0.2%
SEPPmail Secure Email Gateway before version 15.0.1 does not properly sanitize the headers from S/MIME protected MIME entities, allowing an attacker to control trusted headers.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:N
Affected products
SEPPmail · Secure Email GatewayRelated CVEs — SEPPmail Secure Email Gateway
In the same product, most dangerous first.
CVE-2026-27442CRITICALzip_attachments Path TraversalEPSS 0.5%CVE-2026-27441CRITICALPDF Password CMDiEPSS 0.3%CVE-2026-2747MEDIUMPGP Mixed Plaintext and Encrypted ContentEPSS 0.3%CVE-2026-29139HIGHGINA State Confusion Account TakeoverEPSS 0.3%CVE-2026-29135MEDIUMWebmail Password Tag Sanitization BypassEPSS 0.3%CVE-2026-29132MEDIUMESWmail-Verify BypassEPSS 0.3%