diff --git a/src/wp-admin/menu.php b/src/wp-admin/menu.php
index b63e925d799d..a9b89f3fcdeb 100644
--- a/src/wp-admin/menu.php
+++ b/src/wp-admin/menu.php
@@ -308,7 +308,14 @@
 	$submenu['backups.php'][15] = array( __( 'Create New' ), 'backup', 'backup-new.php' );
 }
 
-$_wp_last_utility_menu = 85; // The index of the last top-level menu in the utility menu group.
+if ( ! is_multisite() ) {
+	$menu[90]                     = array( __( 'Debug tools' ), 'safe_mode', 'safe-mode.php', '', 'menu-top menu-icon-settings', 'menu-settings', 'dashicons-database' );
+	if ( \calmpress\calmpress\Safe_Mode::current_user_in_safe_mode() ) {
+		$submenu['safe-mode.php'][10] = array( __( 'Safe Mode' ), 'safe_mode', 'safe-mode.php' );
+	}
+}
+
+$_wp_last_utility_menu = 90; // The index of the last top-level menu in the utility menu group.
 
 $menu[999] = array( '', 'read', 'separator-last', '', 'wp-menu-separator' );
 
diff --git a/src/wp-admin/safe-mode.php b/src/wp-admin/safe-mode.php
new file mode 100644
index 000000000000..087345004f07
--- /dev/null
+++ b/src/wp-admin/safe-mode.php
@@ -0,0 +1,154 @@
+<?php
+/**
+ * Safe mode tools Screen.
+ *
+ * @package calmPress
+ */
+
+declare(strict_types=1);
+
+namespace calmpress\calmpress;
+
+/** WordPress Administration Bootstrap */
+require_once dirname( __FILE__ ) . '/admin.php';
+
+if ( ! current_user_can( 'safe_mode' ) ) {
+	wp_die( esc_html__( 'Sorry, you are not allowed to manage safe mode for this site.' ) );
+}
+
+// Use same styling as maintenance mode.
+wp_enqueue_style( 'maintenance-mode' );
+
+$title       = __( 'Safe Mode' );
+$parent_file = 'tools.php';
+
+get_current_screen()->add_help_tab(
+	array(
+		'id'      => 'overview',
+		'title'   => __( 'Overview' ),
+		'content' =>
+			'<p>' . esc_html__( 'The safe mode enables you to investigate why your normal login fails while ptentially keeping the site running.' ) . '</p>',
+	)
+);
+
+require ABSPATH . 'wp-admin/admin-header.php';
+
+?>
+<div class="wrap metabox-holder">
+	<h1><?php echo esc_html( $title ); ?></h1>
+
+	<div id="status" class="postbox">
+		<h3 class="hndle"><?php esc_html_e( 'Status' ); ?></h3>
+		<div class="inside">
+			<form action="admin-post.php" method="post">
+			<input name='action' type="hidden" value='maintenance_mode_status'>
+			<?php
+			wp_nonce_field( 'maintenance_mode_status' );
+			if ( ! Maintenance_Mode::is_active() ) {
+				echo '<p class="status_line inactive">' . esc_html__( 'Not in maintenance mode' ) . '</p>';
+				echo '<p>';
+				esc_html_e( 'If activated, it is expected to last for:' );
+				?>
+				<br>
+				<input class="hours" type="number" min="0" max="999" name="hours" value="0"> :
+				<input class="minutes" type="number" min="0" max="59" name="minutes" value="00">
+				<?php esc_html_e( 'Hours' ); ?>
+				<?php
+				echo '</p>';
+				echo '<p class="description">' . esc_html__( 'If no value is given, a 10 minutes value will be assumed. If maintenance mode is still active after the expected time it will be prolonged by 10 minutes untile it is deactivated.' ) . '</p>';
+				echo '<p><b>' . esc_html__( 'Before activating maintenance mode you might want to consider changing the setting of your analytics or any other plugin that assume "live" content as plugins keep operating fully.' ) . '</b></p>';
+				submit_button( __( 'Activate maintenance mode' ), 'primary', 'enter' );
+			} else {
+				echo '<p class="status_line active">' . esc_html__( 'In maintenance mode' ) . '</p>';
+				$bypass_url = site_url() . '?' . Maintenance_Mode::BYPASS_NAME . '=' . Maintenance_Mode::bypass_code();
+				?>
+				<p>
+					<?php
+					printf(
+						/* translators: 1: shortcode */
+						esc_html__( 'Bypass maintenance mode with the fillowing URL: %1$s' ),
+						'<code>' . esc_html( $bypass_url ) . '</code>'
+					);
+					?>
+					<br />
+					<span class="description">
+					<?php
+					esc_html_e( 'Once the URL is used, a cookie is set and the user will automatically bypass the maintenance mode for the rest of the session. The URL changes with every maintenance mode activation.' );
+					?>
+					</span>
+				</p>
+				<?php
+				$lasts_for = Maintenance_Mode::projected_time_till_end();
+
+				$hours   = '0';
+				$minutes = '00';
+				if ( $lasts_for <= 10 * MINUTE_IN_SECONDS ) {
+					echo '<p>' . esc_html__( 'Seems like the initialy configured time had passed, try to estimate again.' ) . '<p>';
+				}
+				echo '<p>' . esc_html__( 'Configured to last for another :' );
+				$hours   = intdiv( $lasts_for, 60 * MINUTE_IN_SECONDS );
+				$minutes = sprintf( '%02d', intdiv( $lasts_for % ( 60 * MINUTE_IN_SECONDS ), 60 ) );
+				?>
+				<br>
+				<input class="hours" type="number" min="0" max="999" name="hours" value="<?php echo esc_attr( $hours ); ?>"> :
+				<input class="minutes" type="number" min="0" max="59" name="minutes" value="<?php echo esc_attr( $minutes ); ?>">
+				<?php esc_html_e( 'Hours' ); ?>
+				<?php
+				echo '</p>';
+				echo '<p>';
+				echo '<p><b>' . esc_html__( 'Before deactivating maintenance mode you might want to change back the settings that were changed before activation.' ) . '</b><p>';
+				echo get_submit_button( esc_html__( 'Deactivate maintenance mode' ), 'primary', 'exit', false );
+				echo get_submit_button( esc_html__( 'Change remaining time' ), 'large', 'change_time', false );
+				echo '</p>';
+			}
+			?>
+			</form>
+		</div>
+	</div>
+	<div id="message" class="postbox">
+		<h3 class="hndle"><?php esc_html_e( 'Page content' ); ?></h3>
+		<div class="inside">
+			<p><a target="_blank" href="<?php echo esc_url( wp_nonce_url( site_url(), Maintenance_Mode::PREVIEW_PARAM, Maintenance_Mode::PREVIEW_PARAM ) ); ?>"><?php esc_html_e( 'Preview page' ); ?></a></p>
+			<form action="admin-post.php" method="post">
+				<input name='action' type="hidden" value='maintenance_mode_content'>
+				<?php wp_nonce_field( 'maintenance_mode_content' ); ?>
+				<table class="form-table">
+					<tr><th><label for="page_title"><?php esc_html_e( 'Page title' ); ?></label></th><td><input id="page_title" name="page_title" value="<?php echo esc_attr( Maintenance_Mode::page_title() ); ?>"></td></tr>
+					<tr><th><label for="text_title"><?php esc_html_e( 'Text title' ); ?></label></th><td><input id="text_title" name="text_title" value="<?php echo esc_attr( Maintenance_Mode::text_title() ); ?>"></td></tr>
+					<tr><th><label for="theme_page"><?php esc_html_e( 'Use normal header and footer' ); ?></label></th><td><input id="theme_page" name="theme_page" type="checkbox" <?php checked( Maintenance_Mode::theme_frame_used() ); ?>></td></tr>
+					<tr><th><label><?php esc_html_e( 'Message text' ); ?></label></th></tr>
+					<tr><td colspan="2">
+						<?php
+						$content   = Maintenance_Mode::content();
+						$editor_id = 'message_text';
+						$settings  = [
+							'media_buttons' => true,
+							'wpautop'       => true,
+							'quicktags'     => true,
+							'textarea_rows' => 5,
+						];
+						wp_editor( $content, $editor_id, $settings );
+						?>
+						<p class="description">
+							<?php
+							printf(
+								/* translators: 1: shortcode */
+								esc_html__( 'Use the %1$s shortcode to insert the approximate time left' ),
+								'<code>[maintenance_left]</code>'
+							);
+							?>
+							<br/>
+							<?php
+								esc_html_e( 'Other shortcodes can be used as well but you will need to check if they work as expected.' );
+							?>
+						</p>
+					</td></tr>
+				</table>
+				<?php submit_button(); ?>
+			</form>
+		</div>
+	</div>
+</div>
+
+<?php
+require ABSPATH . 'wp-admin/admin-footer.php';
diff --git a/src/wp-includes/calmpress/autoloader.php b/src/wp-includes/calmpress/autoloader.php
index f948bd9a8a4c..4b291f921ba6 100644
--- a/src/wp-includes/calmpress/autoloader.php
+++ b/src/wp-includes/calmpress/autoloader.php
@@ -60,6 +60,7 @@
 	'calmpress\object_cache\File'                       => __DIR__ . '/object-cache/class-file.php',
 	'calmpress\object_cache\Null_Cache'                 => __DIR__ . '/object-cache/class-null-cache.php',
 	'calmpress\calmpress\Maintenance_Mode'              => __DIR__ . '/calmpress/class-maintenance-mode.php',
+	'calmpress\calmpress\Safe_Mode'                     => __DIR__ . '/calmpress/class-safe-mode.php',
 	'Psr\SimpleCache\CacheInterface'                    => ABSPATH . 'wp-includes/Psr/SimpleCache/CacheInterface.php',
 	'Psr\SimpleCache\CacheException'                    => ABSPATH . 'wp-includes/Psr/SimpleCache/CacheException.php',
 	'Psr\SimpleCache\InvalidArgumentException'          => ABSPATH . 'wp-includes/Psr/SimpleCache/InvalidArgumentException.php',
diff --git a/src/wp-includes/calmpress/calmpress/class-safe-mode.php b/src/wp-includes/calmpress/calmpress/class-safe-mode.php
new file mode 100644
index 000000000000..e33e2dd36b36
--- /dev/null
+++ b/src/wp-includes/calmpress/calmpress/class-safe-mode.php
@@ -0,0 +1,185 @@
+<?php
+/**
+ * Implementation of safe mode related utils.
+ *
+ * @package calmPress
+ * @since 1.0.0
+ */
+
+declare(strict_types=1);
+
+namespace calmpress\calmpress;
+
+/**
+ * Safe mode utils packaged as a class.
+ * 
+ * @since 1.0.0
+ */
+class Safe_Mode {
+
+	/**
+	 * The name of the cookie and URL parameter that might include the bypass code.
+	 *
+	 * @since 1.0.0
+	 */
+	const ACTIVATION_NAME = 'safe_mode';
+
+	/**
+	 * deactivate the maintenance mode..
+	 *
+	 * @since 1.0.0
+	 */
+	public static function deactivate() {
+		update_option( self::OPTION_NAME, '' );
+	}
+
+	/**
+	 * Helper function to set the safe mode cookie, exists mainly to be able to avoid headers
+	 * already sent type of errors during testing.
+	 *
+	 * @since 1.0.0
+	 */
+	protected static function set_safe_mode_cookie() {
+		setcookie( self::ACTIVATION_NAME, 1, 0, COOKIEPATH, COOKIE_DOMAIN, is_ssl() );
+	}
+
+	/**
+	 * Helper function to clear the safe mode cookie, exists mainly to be able to avoid headers
+	 * already sent type of errors during testing.
+	 *
+	 * @since 1.0.0
+	 */
+	protected static function clear_safe_mode_cookie() {
+		setcookie( self::ACTIVATION_NAME, 1, time() - 1000, COOKIEPATH, COOKIE_DOMAIN, is_ssl() );
+	}
+
+	/**
+	 * Indicate if safe mode is active. for this request. To be active the user needs a safe_mode
+	 * capability and a safe_mode parameter specified as a URL parameter or in a cookie.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @return bool true if safe mode is active for the user, false otherwise.
+	 */
+	public static function current_user_in_safe_mode():bool {
+
+		// safe mode via URL paremeter.
+		if ( isset( $_GET[ self::ACTIVATION_NAME ] ) &&
+			current_user_can( 'safe_mode' ) ) {
+			// Set the cookie only for the session.
+			static::set_safe_mode_cookie();
+			return true;
+		}
+
+		// safe mode via cookie.
+		if ( isset( $_COOKIE[ self::ACTIVATION_NAME ] ) &&
+			current_user_can( 'safe_mode' ) ) {
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	 * Exit the current user from safe mode.
+	 *
+	 * Bsically removes the safe mode cookie. Usage of URL parameter can still put the user
+	 * into safe mode.
+	 *
+	 * @since 1.0.0
+	 */
+	public static function exit_safe_mode():bool {
+
+		static::clear_safe_mode_cookie();
+	}
+
+	/**
+	 * Verify capability, nonce, and validitty of referer data a POST request. Die if the
+	 * user is not allowed to changed safe mode related data, or nonce/referer include
+	 * bad data. 
+	 *
+	 * @since 1.0.0
+	 *
+	 * @param string $action The name of the action expected to be used for generating the nonce
+	 *                       and admin referer fields in the request.
+	 */
+	private static function verify_post_request( string $action ) {
+		if ( ! current_user_can( 'safe_mode' ) ) {
+			wp_die(
+				'<h1>' . __( 'You need additional permission.' ) . '</h1>' .
+				'<p>' . __( 'Sorry, you are not allowed to manage safe mode for this site.' ) . '</p>',
+				403
+			);
+		}
+		check_admin_referer( $action );
+	}
+
+	/**
+	 * Handles the form post regarding content related maintenance page changes. Updates the
+	 * post holding the content data.
+	 *
+	 * Used as a hook on admin-post.
+	 *
+	 * @since 1.0.0
+	 */
+	public static function handle_content_change_post() {
+		$errors = [];
+		static::verify_post_request( 'maintenance_mode_content' );
+
+		if ( ! isset( $_POST['page_title'] ) || ! isset( $_POST['text_title'] ) || ! isset( $_POST['message_text'] ) ) {
+			$errors[] = esc_html__( 'Something went wrong, please try again' );
+		} else {
+			static::set_page_title( wp_unslash( $_POST['page_title'] ) );
+			static::set_text_title( wp_unslash( $_POST['text_title'] ) );
+			static::set_content( wp_unslash( $_POST['message_text'] ) );
+			static::set_use_theme_frame( isset( $_POST['theme_page'] ) );
+		}
+
+		set_transient( 'maintenance_mode_errors', $errors, 30 );	
+	
+		// Redirect back to the settings page that was submitted.
+		$goback = add_query_arg( 'settings-updated', 'true', wp_get_referer() );
+		wp_redirect( $goback );
+		exit;			
+	}
+
+	/**
+	 * Handle the form post regarding maintenance mode (de)activation. Updates the activation state
+	 * and/or the interval till expected end of it.
+	 *
+	 * Used as a hook on admin-post.
+	 *
+	 * @since 1.0.0
+	 */
+	public static function handle_status_change_post() {
+		$errors = [];
+		static::verify_post_request( 'maintenance_mode_status' );
+
+		// Check basic validity.
+		if ( ! isset( $_POST['hours'] ) || ! isset( $_POST['minutes'] ) ) {
+			$errors[] = esc_html__( 'Something went wrong, please try again' );
+		} else {
+			// Not putting much effort in validating the values as out of expected range
+			// values can not do any harm.
+			$hours    = (int) wp_unslash( $_POST['hours'] );
+			$minutes  = (int) wp_unslash( $_POST['minutes'] );
+			$end_time = time() + ( 60 * $hours + $minutes ) * 60;
+			static::set_projected_end_time( $end_time );
+
+			if ( isset( $_POST['enter'] ) ) {
+				static::activate();
+			}
+
+			if ( isset( $_POST['exit'] ) ) {
+				static::deactivate();
+			}
+		}
+
+		set_transient( 'maintenance_mode_errors', $errors, 30 );	
+	
+		// Redirect back to the settings page that was submitted.
+		$goback = add_query_arg( 'settings-updated', 'true', wp_get_referer() );
+		wp_redirect( $goback );
+		exit;			
+	}
+}