Index: src/wp-includes/class-wp-customize-control.php
===================================================================
--- src/wp-includes/class-wp-customize-control.php	(revision 33191)
+++ src/wp-includes/class-wp-customize-control.php	(working copy)
@@ -1577,10 +1577,10 @@
 			<?php _e( 'Add Items' ); ?>
 		</button>
 		<button type="button" role="presentation" class="not-a-button reorder-toggle" tabindex="-1">
-			<span class="reorder" tabindex="0" role="button" aria-label="<?php esc_attr_e( 'Reorder menu items' ); ?>" aria-describedby="reorder-items-desc"><?php _ex( 'Reorder', 'Reorder menu items in Customizer' ); ?></span>
+			<span class="reorder" tabindex="0" role="button" aria-label="<?php esc_attr_e( 'Reorder menu items' ); ?>" aria-describedby="reorder-items-desc-{{ data.menu_id }}"><?php _ex( 'Reorder', 'Reorder menu items in Customizer' ); ?></span>
 			<span class="reorder-done" tabindex="0" role="button" aria-label="<?php esc_attr_e( 'Close reorder mode' ); ?>"><?php _ex( 'Done', 'Cancel reordering menu items in Customizer' ); ?></span>
 		</button>
-		<p class="screen-reader-text" id="reorder-items-desc"><?php _e( 'When in reorder mode, additional controls to reorder menu items will be available in the items list above.' ); ?></p>
+		<p class="screen-reader-text" id="reorder-items-desc-{{ data.menu_id }}"><?php _e( 'When in reorder mode, additional controls to reorder menu items will be available in the items list above.' ); ?></p>
 		<span class="add-menu-item-loading spinner"></span>
 		<span class="menu-delete-item">
 			<button type="button" class="not-a-button menu-delete">