When Velociraptor is configured to use an OIDC IdP for authentication, it uses the email claim as...

When Velociraptor is configured to use an OIDC IdP for authentication, it uses the email claim as a username. However, some IdP allow users to change the email claim without verification. Some IdPs do not set the "email_verified" claim and do not actually verify the email.

This allows a user to impersonate another user by setting their email address within the IdP, allowing account takeover.