diff --git a/core/modules/comment/src/CommentTypeListBuilder.php b/core/modules/comment/src/CommentTypeListBuilder.php
index 248a5d5..f813665 100644
--- a/core/modules/comment/src/CommentTypeListBuilder.php
+++ b/core/modules/comment/src/CommentTypeListBuilder.php
@@ -47,7 +47,7 @@ public function buildHeader() {
   public function buildRow(EntityInterface $entity) {
     $row['type'] = SafeMarkup::checkPlain($entity->label());
     // #markup is filtered for admin XSS automatically.
-    $row['description']['data']['#markup'] = $entity->getDescription();
+    $row['description']['data'] = ['#markup' => $entity->getDescription()];
     return $row + parent::buildRow($entity);
   }
 
diff --git a/core/modules/menu_ui/src/MenuListBuilder.php b/core/modules/menu_ui/src/MenuListBuilder.php
index 86a7a12..9b5a171 100644
--- a/core/modules/menu_ui/src/MenuListBuilder.php
+++ b/core/modules/menu_ui/src/MenuListBuilder.php
@@ -40,7 +40,7 @@ public function buildRow(EntityInterface $entity) {
       'class' => array('menu-label'),
     );
     // #markup is filtered for admin XSS automatically.
-    $row['description']['data']['#markup'] = $entity->getDescription();
+    $row['description']['data'] = ['#markup' => $entity->getDescription()];
     return $row + parent::buildRow($entity);
   }
 
diff --git a/core/modules/node/node.module b/core/modules/node/node.module
index 1d3c46e..940142e 100644
--- a/core/modules/node/node.module
+++ b/core/modules/node/node.module
@@ -510,7 +510,7 @@ function template_preprocess_node_add_list(&$variables) {
         'type' => $type->id(),
         'add_link' => \Drupal::l($type->label(), new Url('node.add', array('node_type' => $type->id()))),
         'description' => array(
-          // The description will XSS filtered by the render system.
+          // #markup is filtered for admin XSS automatically.
           '#markup' => $type->getDescription(),
         ),
       );
diff --git a/core/modules/node/src/NodeTypeListBuilder.php b/core/modules/node/src/NodeTypeListBuilder.php
index 4e162a2..9f764cd 100644
--- a/core/modules/node/src/NodeTypeListBuilder.php
+++ b/core/modules/node/src/NodeTypeListBuilder.php
@@ -40,7 +40,7 @@ public function buildRow(EntityInterface $entity) {
       'class' => array('menu-label'),
     );
     // #markup is filtered for admin XSS automatically.
-    $row['description']['data']['#markup'] = $entity->getDescription();
+    $row['description']['data'] = ['#markup' => $entity->getDescription()];
     return $row + parent::buildRow($entity);
   }
 
diff --git a/core/modules/system/src/Plugin/Block/SystemBrandingBlock.php b/core/modules/system/src/Plugin/Block/SystemBrandingBlock.php
index 16b0368..88aa877 100644
--- a/core/modules/system/src/Plugin/Block/SystemBrandingBlock.php
+++ b/core/modules/system/src/Plugin/Block/SystemBrandingBlock.php
@@ -174,6 +174,7 @@ public function build() {
     );
 
     $build['site_slogan'] = array(
+      // #markup is filtered for admin XSS automatically.
       '#markup' => $site_config->get('slogan'),
       '#access' => $this->configuration['use_site_slogan'],
     );
diff --git a/core/modules/system/system.admin.inc b/core/modules/system/system.admin.inc
index 1141a35..a7cabee 100644
--- a/core/modules/system/system.admin.inc
+++ b/core/modules/system/system.admin.inc
@@ -58,6 +58,7 @@ function template_preprocess_admin_block_content(&$variables) {
     foreach ($variables['content'] as $key => $item) {
       $variables['content'][$key]['link'] = \Drupal::l($item['title'], $item['url']);
       if (!$variables['compact'] && isset($item['description'])) {
+        // #markup is filtered for admin XSS automatically.
         $variables['content'][$key]['description'] = ['#markup' => $item['description']];
       }
       else {
diff --git a/core/modules/views_ui/views_ui.module b/core/modules/views_ui/views_ui.module
index 48d70f6..5b43ad1 100644
--- a/core/modules/views_ui/views_ui.module
+++ b/core/modules/views_ui/views_ui.module
@@ -129,8 +129,9 @@ function views_ui_preprocess_views_view(&$variables) {
 
   // Render title for the admin preview.
   if (!empty($view->live_preview)) {
-    // #markup is filtered for admin XSS automatically.
-    $variables['title']['#markup'] = $view->getTitle();
+    // The title will be autoescaped by Twig so it is not necessary to XSS
+    // filter it.
+    $variables['title'] = $view->getTitle();
   }
 
   if (!empty($view->live_preview) && \Drupal::moduleHandler()->moduleExists('contextual')) {