Chat Server is the chat server for Vartalap, an open-source messaging application. Versions 2.3.2 until 2.6.0 suffer from a bug in validating the access token, resulting in authentication bypass. The function "this.authProvider.verifyAccessKey" is an async function, as the code is not using "await" to wait for the verification result. Every time the function responds back with success, along with an unhandled exception if the token is invalid. A patch is available in version 2.6.0.