CODE EXAMPLE FOR PHP

woocommerce php reset password length

add_action( 'validate_password_reset' , 'se_password_min_length_check' 10, 2 );

function se_password_min_length_check( $errors, $user){
    if(strlen($_POST['pass1']) < 8)
        $errors->add( 'password_too_short', 'ERROR: password is too short.' );
}