CVE-2021-38373: Kde Kmail

Medium severity, CVSS 5.3. EPSS: 0.5% chance of exploitation in the next 30 days.

In KDE KMail 19.12.3 (aka 5.13.3), the SMTP STARTTLS option is not honored (and cleartext messages are sent) unless "Server requires authentication" is checked.

Affected products

• Kde Kmail: version 19.12.3 only

Published 2021-08-10. Last modified 2026-06-17.