Ticket #58471: 58471-1.diff

src/wp-includes/cron.php

@@ -845 +845 @@
          * Multiple processes on multiple web servers can run this code concurrently,
          * this lock attempts to make spawning as atomic as possible.
          */
-        $lock = get_transient( 'doing_cron' );
+        $lock = (int) get_transient( 'doing_cron' );
 
         if ( $lock > $gmt_time + 10 * MINUTE_IN_SECONDS ) {
                 $lock = 0;