CVE-2021-37862: Mattermost Server

Medium severity, CVSS 5.4. EPSS: 0.7% chance of exploitation in the next 30 days.

Mattermost 6.0 and earlier fails to sufficiently validate the email address during registration, which allows attackers to trick users into signing up using attacker-controlled email addresses via crafted invitation token.

Affected products

• Mattermost Mattermost Server: up to and including 6.0

Published 2021-12-17. Last modified 2026-06-17.