diff --git a/wp-admin/edit-form-blocks.php b/wp-admin/edit-form-blocks.php
index 4e104feda2..c1c37487ef 100644
--- a/wp-admin/edit-form-blocks.php
+++ b/wp-admin/edit-form-blocks.php
@@ -69,7 +69,7 @@ $preload_paths = apply_filters( 'block_editor_preload_paths', $preload_paths, $p
  * Because API preloading can call the_content and other filters, plugins
  * can unexpectedly modify $post.
  */
-$backup_global_post = $post;
+$backup_global_post = clone $post;
 
 $preload_data = array_reduce(
 	$preload_paths,
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 622d4071ee..bb4374ad51 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.6-alpha-48699';
+$wp_version = '5.6-alpha-48700';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.