Nextcloud mail is an email app for the nextcloud home server platform. In versions prior to 2.2.2 user's passwords were stored in cleartext in the database during the duration of OAuth2 setup procedure. Any attacker or malicious user with access to the database would have access to these user passwords until the OAuth setup has been completed. It is recommended that the Nextcloud Mail app is upgraded to 2.2.2. There are no known workarounds for this issue.