Stored Cross-site Scripting (CWE-79) in the email module in Roskus Prospero Flow CRM before 5.4.4 allows a remote, authenticated low-privileged user to execute arbitrary JavaScript in another user's browser, including administrators, leading to session compromise and account takeover, via a payload stored in an email body that is persisted without sanitization and rendered unescaped with {!! $email->body !!} when the recipient opens the message.