--- a/wp/wp-content/themes/twentythirteen/taxonomy-post_format.php	Mon Jun 08 16:11:51 2015 +0000
+++ b/wp/wp-content/themes/twentythirteen/taxonomy-post_format.php	Tue Jun 09 03:35:32 2015 +0200
@@ -6,7 +6,7 @@
  * If you'd like to further customize these Post Format views, you may create a
  * new template file for each specific one.
  *
- * @link http://codex.wordpress.org/Template_Hierarchy
+ * @link https://codex.wordpress.org/Template_Hierarchy
  *
  * @package WordPress
  * @subpackage Twenty_Thirteen
@@ -20,7 +20,7 @@
 
 		<?php if ( have_posts() ) : ?>
 			<header class="archive-header">
-				<h1 class="archive-title"><?php printf( __( '%s Archives', 'twentythirteen' ), '<span>' . get_post_format_string( get_post_format() ) . '</span>' ); ?></h1>
+				<h1 class="archive-title"><?php printf( __( '%s Archives', 'twentythirteen' ), '<span>' . esc_html( get_post_format_string( get_post_format() ) ) . '</span>' ); ?></h1>
 			</header><!-- .archive-header -->
 
 			<?php /* The loop */ ?>
@@ -38,4 +38,4 @@
 	</div><!-- #primary -->
 
 <?php get_sidebar(); ?>
-<?php get_footer(); ?>
\ No newline at end of file
+<?php get_footer(); ?>