CVE-2020-12619: Freron Mailmate

Medium severity, CVSS 5.9. EPSS: 0.4% chance of exploitation in the next 30 days.

MailMate before 1.11 automatically imported S/MIME certificates and thereby silently replaced existing ones. This allowed a man-in-the-middle attacker to obtain an email-validated S/MIME certificate from a trusted CA and replace the public key of the entity to be impersonated. This enabled the attacker to decipher further communication. The entire attack could be accomplished by sending a single email.

Affected products

• Freron Mailmate: before 1.11 (fixed in 1.11)

Published 2020-08-20. Last modified 2026-06-17.