Ticket #40861: 40861.patch

src/wp-includes/post.php

@@ -3608 +3608 @@
 
         if ( 'attachment' === $postarr['post_type'] ) {
                 if ( ! empty( $postarr['file'] ) ) {
-                        update_attached_file( $post_ID, $postarr['file'] );
+                        update_attached_file( $post_ID, wp_unslash( $postarr['file'] ) );
                 }
 
                 if ( ! empty( $postarr['context'] ) ) {