ZITADEL is an identity infrastructure system. ZITADEL uses the notification triggering requests Forwarded or X-Forwarded-Host header to build the button link sent in emails for confirming a password reset with the emailed code. If this header is overwritten and a user clicks the link to a malicious site in the email, the secret code can be retrieved and used to reset the users password and take over his account.

Accounts with MFA or Passwordless enabled can not be taken over by this attack. This issue has been patched in versions 2.41.6, 2.40.10 and 2.39.9.