Ticket #48848: 48848.patch

src/wp-mail.php

@@ -171 +171 @@
                         $content = explode( $delim[0], $content );
                         $content = $content[1];
                 }
-                $content = strip_tags( $content, '<img><p><br><i><b><u><em><strong><strike><font><span><div>' );
+                $content = strip_tags( $content, ['img','p', 'br', 'i', 'b', 'u', 'em', 'strong', 'strike', 'font', 'span', 'div'] );
         }
         $content = trim( $content );