WordPress at a glance
action is not described

wp_login_failed action-hook . WP 2.5.0

Fires after a user login has failed.

Usage

add_action( 'wp_login_failed', 'action_function_name_7444', 10, 2 );
function action_function_name_7444( $username, $error ){
	// action...
}
$username(string)
Username or email address.
$error(WP_Error)
A WP_Error object with the authentication failure details.

Changelog

Since 2.5.0 Introduced.
Since 4.5.0 The value of $username can now be an email address.
Since 5.4.0 The $error parameter was added.

Where the hook is called

wp_authenticate()
wp_login_failed
wp-includes/pluggable.php 562
do_action( 'wp_login_failed', $username, $error );

Where in WP core the hook is used

Usage not found!