NATS-Server, a high-performance messaging system server, contains a vulnerability where MQTT passwords are incorrectly classified as non-authenticating JWT statements and exposed through monitoring endpoints. The issue affects versions prior to 2.11.15 and 2.12.6. Fixed versions 2.11.14 and 2.12.6 are available. As a workaround, organizations should secure monitoring endpoints and avoid exposing them to untrusted networks. The vulnerability specifically impacts MQTT deployments using username/password authentication.