diff --git a/wp-includes/class-wp-block-supports.php b/wp-includes/class-wp-block-supports.php
index afc011803b..c90b5e0c54 100644
--- a/wp-includes/class-wp-block-supports.php
+++ b/wp-includes/class-wp-block-supports.php
@@ -103,7 +103,7 @@ class WP_Block_Supports {
 			return array();
 		}
 
-		$block_attributes = array_key_exists( 'attrs', self::$block_to_render )
+		$block_attributes = array_key_exists( 'attrs', self::$block_to_render ) && is_array( self::$block_to_render['attrs'] )
 			? self::$block_to_render['attrs']
 			: array();
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 1c24044b62..6052ce7797 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.6-alpha-58111';
+$wp_version = '6.6-alpha-58112';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.