diff --git a/wp-includes/formatting.php b/wp-includes/formatting.php
index 0441866344..eb4acda64b 100644
--- a/wp-includes/formatting.php
+++ b/wp-includes/formatting.php
@@ -4639,11 +4639,11 @@ EOF;
 	$safe_text = (string) preg_replace_callback(
 		$regex,
 		static function( $matches ) {
-			if ( ! $matches[0] ) {
+			if ( ! isset( $matches[0] ) ) {
 				return '';
 			}
 
-			if ( ! empty( $matches['non_cdata'] ) ) {
+			if ( isset( $matches['non_cdata'] ) ) {
 				// escape HTML entities in the non-CDATA Section.
 				return _wp_specialchars( $matches['non_cdata'], ENT_XML1 );
 			}
diff --git a/wp-includes/version.php b/wp-includes/version.php
index c3e0c5e681..5df481479f 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.0-alpha-53143';
+$wp_version = '6.0-alpha-53144';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.