diff --git a/wp-includes/theme-compat/embed-content.php b/wp-includes/theme-compat/embed-content.php
index f706c6833d..c77026bd67 100644
--- a/wp-includes/theme-compat/embed-content.php
+++ b/wp-includes/theme-compat/embed-content.php
@@ -22,6 +22,15 @@
 			$thumbnail_id = get_the_ID();
 		}
 
+		/**
+		 * Filters the thumbnail image ID for use in the embed template.
+		 *
+		 * @since 4.9.0
+		 *
+		 * @param int $thumbnail_id Attachment ID.
+		 */
+		$thumbnail_id = apply_filters( 'embed_thumbnail_id', $thumbnail_id );
+
 		if ( $thumbnail_id ) {
 			$aspect_ratio = 1;
 			$measurements = array( 1, 1 );
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 9097909683..1d561bbd10 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.9-alpha-41564';
+$wp_version = '4.9-alpha-41565';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.