Sketch: Use wp_kses_post rather than wp_filter_post_kses. See 5019-wpcom-themes.

sketch/inc/jetpack.php

@@ -116,7 +116,7 @@ function sketch_portfolio_content( $before = '', $after = '' ) {
 	if ( is_tax() && get_the_archive_description() ) {
 		echo $before . get_the_archive_description() . $after;
 	} else if ( isset( $jetpack_portfolio_content ) && '' != $jetpack_portfolio_content ) {
-		$content = convert_chars( convert_smilies( wptexturize( stripslashes( wp_filter_post_kses( addslashes( $jetpack_portfolio_content ) ) ) ) ) );
+		$content = convert_chars( convert_smilies( wptexturize( wp_kses_post( $jetpack_portfolio_content ) ) ) );
 		echo $before . $content . $after;
 	}
 }
@@ -143,4 +143,4 @@ function sketch_portfolio_infinite_scroll_navigation( $js_settings ) {
 
 	return $js_settings;
 }
-add_filter( 'infinite_scroll_js_settings', 'sketch_portfolio_infinite_scroll_navigation' );
+add_filter( 'infinite_scroll_js_settings', 'sketch_portfolio_infinite_scroll_navigation' );

sketch/style.css

@@ -4,7 +4,7 @@ Theme URI: https://wordpress.com/themes/sketch/
 Author: Automattic
 Author URI: https://wordpress.com/themes/
 Description: A clean, responsive portfolio theme with options for a custom site logo, a featured content slider, and lots of room to share your work.
-Version: 1.2.3-wpcom
+Version: 1.2.4-wpcom
 License: GNU General Public License v2 or later
 License URI: http://www.gnu.org/licenses/gpl-2.0.html
 Text Domain: sketch