diff --git a/wp-includes/blocks.php b/wp-includes/blocks.php
index aebb4b4065..097c3b8841 100644
--- a/wp-includes/blocks.php
+++ b/wp-includes/blocks.php
@@ -1376,10 +1376,15 @@ function build_query_vars_from_query_block( $block, $page ) {
 			$query['orderby'] = $block->context['query']['orderBy'];
 		}
 		if (
-			isset( $block->context['query']['author'] ) &&
-			(int) $block->context['query']['author'] > 0
+			isset( $block->context['query']['author'] )
 		) {
-			$query['author'] = (int) $block->context['query']['author'];
+			if ( is_array( $block->context['query']['author'] ) ) {
+				$query['author__in'] = array_filter( array_map( 'intval', $block->context['query']['author'] ) );
+			} elseif ( is_string( $block->context['query']['author'] ) ) {
+				$query['author__in'] = array_filter( array_map( 'intval', explode( ',', $block->context['query']['author'] ) ) );
+			} elseif ( is_int( $block->context['query']['author'] ) && $block->context['query']['author'] > 0 ) {
+				$query['author'] = $block->context['query']['author'];
+			}
 		}
 		if ( ! empty( $block->context['query']['search'] ) ) {
 			$query['s'] = $block->context['query']['search'];
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 87ebda3dc8..f3bd4d342a 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.3-beta2-56108';
+$wp_version = '6.3-beta2-56109';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.