A vulnerability in the application authentication and authorization mechanism in Hitachi Energy's TXpert Hub CoreTec 4, that depends on a token validation of the session identifier, allows an unauthorized modified message to be executed in the server enabling an unauthorized actor to change an existing user password, and further gain authorized access into the system via login mechanism. This issue affects: Hitachi Energy TXpert Hub CoreTec 4 version 2.0.0 2.1.0; 2.1.0; 2.1.1; 2.1.2; 2.1.3; 2.2.0; 2.2.1.