diff --git a/wp-includes/class-wp-block.php b/wp-includes/class-wp-block.php
index 455ea2e138..0145ba4369 100644
--- a/wp-includes/class-wp-block.php
+++ b/wp-includes/class-wp-block.php
@@ -241,7 +241,7 @@ class WP_Block {
 			'core/paragraph' => array( 'content' ),
 			'core/heading'   => array( 'content' ),
 			'core/image'     => array( 'url', 'title', 'alt' ),
-			'core/button'    => array( 'url', 'text' ),
+			'core/button'    => array( 'url', 'text', 'linkTarget', 'rel' ),
 		);
 
 		// If the block doesn't have the bindings property, isn't one of the allowed
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 4b5e3d5cf1..6c67085712 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.5-alpha-57575';
+$wp_version = '6.5-alpha-57576';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.