Index: class-wp-comments-list-table.php
===================================================================
--- class-wp-comments-list-table.php	(revision 40877)
+++ class-wp-comments-list-table.php	(working copy)
@@ -685,7 +685,7 @@
 
 		echo "<strong>"; comment_author( $comment ); echo '</strong><br />';
 		if ( ! empty( $author_url_display ) ) {
-			printf( '<a href="%s">%s</a><br />', esc_url( $author_url ), esc_html( $author_url_display ) );
+			printf( '<a href="%s" rel="noopener noreferrer" target="_blank">%s</a><br />', esc_url( $author_url ), esc_html( $author_url_display ) );
 		}
 
 		if ( $this->user_can ) {