WordPress at a glance
filter is not described

wp_login_errors filter-hook . WP 3.6.0

Filters the login page errors.

Usage

add_filter( 'wp_login_errors', 'filter_function_name_9844', 10, 2 );
function filter_function_name_9844( $errors, $redirect_to ){
	// filter...

	return $errors;
}
$errors(object)
WP Error object.
$redirect_to(string)
Redirect destination URL.

Where the hook is called

In file: /wp-login.php
wp_login_errors
wp-login.php 983
$errors = apply_filters( 'wp_login_errors', $errors, $redirect_to );

Where the hook is used (in WP core)

Does not used.