A vulnerability in rustls versions prior to 0.23.46 and between 0.24.0-dev.1 and 0.24.0-dev.2 allows the TLS master secret or TLS 1.3 resumption PSK to be exposed when formatting a client session value with the Debug trait. This can lead to leakage of sensitive key material if a custom ClientSessionStore logs these debug outputs. Built-in diagnostics do not expose these secrets, and the session-store interface warns about the sensitivity of these values.