diff --git a/wp-admin/includes/media.php b/wp-admin/includes/media.php
index 4c8a04d5c1..6bb541dd35 100644
--- a/wp-admin/includes/media.php
+++ b/wp-admin/includes/media.php
@@ -2899,6 +2899,10 @@ function attachment_submitbox_metadata() {
 		endif;
 
 	if ( preg_match( '#^(audio|video)/#', $post->post_mime_type ) ) {
+		$fields = array(
+			'length_formatted' => __( 'Length:' ),
+			'bitrate'          => __( 'Bitrate:' ),
+		);
 
 		/**
 		 * Filters the audio and video metadata fields to be shown in the publish meta box.
@@ -2907,13 +2911,12 @@ function attachment_submitbox_metadata() {
 		 * metadata key, and the value should be the desired label.
 		 *
 		 * @since 3.7.0
+		 * @since 4.9.0 Added the `$post` parameter.
 		 *
-		 * @param array $fields An array of the attachment metadata keys and labels.
+		 * @param array   $fields An array of the attachment metadata keys and labels.
+		 * @param WP_Post $post   WP_Post object for the current attachment.
 		 */
-		$fields = apply_filters( 'media_submitbox_misc_sections', array(
-			'length_formatted' => __( 'Length:' ),
-			'bitrate'          => __( 'Bitrate:' ),
-		) );
+		$fields = apply_filters( 'media_submitbox_misc_sections', $fields, $post );
 
 		foreach ( $fields as $key => $label ) {
 			if ( empty( $meta[ $key ] ) ) {
@@ -2938,6 +2941,11 @@ function attachment_submitbox_metadata() {
 	<?php
 		}
 
+		$fields = array(
+			'dataformat' => __( 'Audio Format:' ),
+			'codec'      => __( 'Audio Codec:' )
+		);
+
 		/**
 		 * Filters the audio attachment metadata fields to be shown in the publish meta box.
 		 *
@@ -2945,13 +2953,12 @@ function attachment_submitbox_metadata() {
 		 * metadata key, and the value should be the desired label.
 		 *
 		 * @since 3.7.0
+		 * @since 4.9.0 Added the `$post` parameter.
 		 *
-		 * @param array $fields An array of the attachment metadata keys and labels.
+		 * @param array   $fields An array of the attachment metadata keys and labels.
+		 * @param WP_Post $post   WP_Post object for the current attachment.
 		 */
-		$audio_fields = apply_filters( 'audio_submitbox_misc_sections', array(
-			'dataformat' => __( 'Audio Format:' ),
-			'codec'      => __( 'Audio Codec:' )
-		) );
+		$audio_fields = apply_filters( 'audio_submitbox_misc_sections', $fields, $post );
 
 		foreach ( $audio_fields as $key => $label ) {
 			if ( empty( $meta['audio'][ $key ] ) ) {
diff --git a/wp-admin/includes/meta-boxes.php b/wp-admin/includes/meta-boxes.php
index e3511faf67..1bc057141d 100644
--- a/wp-admin/includes/meta-boxes.php
+++ b/wp-admin/includes/meta-boxes.php
@@ -244,8 +244,12 @@ do_action( 'post_submitbox_misc_actions', $post );
  * Fires at the beginning of the publishing actions section of the Publish meta box.
  *
  * @since 2.7.0
+ * @since 4.9.0 Added the `$post` parameter.
+ *
+ * @param WP_Post|null $post WP_Post object for the current post on Edit Post screen,
+ *                           null on Edit Link screen.
  */
-do_action( 'post_submitbox_start' );
+do_action( 'post_submitbox_start', $post );
 ?>
 <div id="delete-action">
 <?php
@@ -326,8 +330,11 @@ function attachment_submit_meta_box( $post ) {
 	 * in the attachment editing screen.
 	 *
 	 * @since 3.5.0
+	 * @since 4.9.0 Added the `$post` parameter.
+	 *
+	 * @param WP_Post $post WP_Post object for the current attachment. 
 	 */
-	do_action( 'attachment_submitbox_misc_actions' );
+	do_action( 'attachment_submitbox_misc_actions', $post );
 	?>
 </div><!-- #misc-publishing-actions -->
 <div class="clear"></div>
@@ -914,7 +921,7 @@ function link_submit_meta_box($link) {
 <div id="major-publishing-actions">
 <?php
 /** This action is documented in wp-admin/includes/meta-boxes.php */
-do_action( 'post_submitbox_start' );
+do_action( 'post_submitbox_start', null );
 ?>
 <div id="delete-action">
 <?php
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 6044e85db0..ad007cd0b7 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.9-alpha-41580';
+$wp_version = '4.9-alpha-41581';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.