Rocket.Chat is an open-source, secure, fully customizable communications platform. Prior to 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, and 7.10.13, the POST /api/v1/fingerprint REST endpoint enforces authentication (authRequired: true) but performs no authorization check. Any authenticated user — including a standard user role account — can call this endpoint with {"setDeploymentAs": "new-workspace"} to permanently deregister the workspace from Rocket.Chat Cloud. This wipes all cloud credentials, removes the workspace license, breaks push notifications for all users, and requires manual re-registration to recover. This vulnerability is fixed in 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, and 7.10.13.