diff --git a/core/lib/Drupal/Core/Render/Element/Button.php b/core/lib/Drupal/Core/Render/Element/Button.php
index 11a9093..5d1989b 100644
--- a/core/lib/Drupal/Core/Render/Element/Button.php
+++ b/core/lib/Drupal/Core/Render/Element/Button.php
@@ -36,6 +36,7 @@ public function getInfo() {
         array($class, 'processAjaxForm'),
       ),
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderButton'),
       ),
       '#theme_wrappers' => array('input__submit'),
diff --git a/core/lib/Drupal/Core/Render/Element/Checkbox.php b/core/lib/Drupal/Core/Render/Element/Checkbox.php
index 43b37ca..4be489b 100644
--- a/core/lib/Drupal/Core/Render/Element/Checkbox.php
+++ b/core/lib/Drupal/Core/Render/Element/Checkbox.php
@@ -33,6 +33,7 @@ public function getInfo() {
         array($class, 'processGroup'),
       ),
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderCheckbox'),
         array($class, 'preRenderGroup'),
       ),
diff --git a/core/lib/Drupal/Core/Render/Element/Checkboxes.php b/core/lib/Drupal/Core/Render/Element/Checkboxes.php
index aa3b64c..41315a0 100644
--- a/core/lib/Drupal/Core/Render/Element/Checkboxes.php
+++ b/core/lib/Drupal/Core/Render/Element/Checkboxes.php
@@ -36,6 +36,7 @@ public function getInfo() {
         array($class, 'processCheckboxes'),
       ),
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderCompositeFormElement'),
       ),
       '#theme_wrappers' => array('checkboxes'),
diff --git a/core/lib/Drupal/Core/Render/Element/Color.php b/core/lib/Drupal/Core/Render/Element/Color.php
index fa05799..341c21d 100644
--- a/core/lib/Drupal/Core/Render/Element/Color.php
+++ b/core/lib/Drupal/Core/Render/Element/Color.php
@@ -32,6 +32,7 @@ public function getInfo() {
         array($class, 'validateColor'),
       ),
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderColor'),
       ),
       '#theme' => 'input__color',
diff --git a/core/lib/Drupal/Core/Render/Element/Date.php b/core/lib/Drupal/Core/Render/Element/Date.php
index 8585cb3..d92145d 100644
--- a/core/lib/Drupal/Core/Render/Element/Date.php
+++ b/core/lib/Drupal/Core/Render/Element/Date.php
@@ -30,6 +30,7 @@ public function getInfo() {
       '#input' => TRUE,
       '#theme' => 'input__date',
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderDate'),
       ),
       '#theme_wrappers' => array('form_element'),
diff --git a/core/lib/Drupal/Core/Render/Element/Email.php b/core/lib/Drupal/Core/Render/Element/Email.php
index c17633f..22c7286 100644
--- a/core/lib/Drupal/Core/Render/Element/Email.php
+++ b/core/lib/Drupal/Core/Render/Element/Email.php
@@ -48,6 +48,7 @@ public function getInfo() {
         array($class, 'validateEmail'),
       ),
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderEmail'),
       ),
       '#theme' => 'input__email',
diff --git a/core/lib/Drupal/Core/Render/Element/File.php b/core/lib/Drupal/Core/Render/Element/File.php
index 848e401..09e9b75 100644
--- a/core/lib/Drupal/Core/Render/Element/File.php
+++ b/core/lib/Drupal/Core/Render/Element/File.php
@@ -30,6 +30,7 @@ public function getInfo() {
       ),
       '#size' => 60,
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderFile'),
       ),
       '#theme' => 'input__file',
diff --git a/core/lib/Drupal/Core/Render/Element/FormElement.php b/core/lib/Drupal/Core/Render/Element/FormElement.php
index 401c850..b22795f 100644
--- a/core/lib/Drupal/Core/Render/Element/FormElement.php
+++ b/core/lib/Drupal/Core/Render/Element/FormElement.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\Render\Element;
 
+use Drupal\Component\Utility\Xss;
 use Drupal\Core\Form\FormStateInterface;
 
 /**
@@ -21,6 +22,44 @@
  */
 abstract class FormElement extends RenderElement implements FormElementInterface {
 
+ /**
+   * {@inheritdoc}
+   */
+  public function getInfo() {
+    $class = get_class($this);
+    return array(
+      '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
+      ),
+    );
+  }
+
+  /**
+   * Pre-render callback: XSS filter dangerous properties that may contain HTML.
+   *
+   * @param array $element
+   *
+   * @return array
+   *   The passed-in element.
+   */
+  public static function preRenderFormElement($element) {
+    // Filtering keys which are expected to contain HTML.
+    $markup_keys = array(
+      '#description',
+      '#field_prefix',
+      '#field_suffix',
+    );
+    foreach ($markup_keys as $key) {
+      if (!empty($element[$key]) && !is_array($element[$key])) {
+        $element[$key] = Xss::filterAdmin($element[$key]);
+      }
+      else {
+        $element[$key] = NULL;
+      }
+    }
+    return $element;
+  }
+
   /**
    * {@inheritdoc}
    */
diff --git a/core/lib/Drupal/Core/Render/Element/Hidden.php b/core/lib/Drupal/Core/Render/Element/Hidden.php
index bb955af..1798924 100644
--- a/core/lib/Drupal/Core/Render/Element/Hidden.php
+++ b/core/lib/Drupal/Core/Render/Element/Hidden.php
@@ -29,6 +29,7 @@ public function getInfo() {
         array($class, 'processAjaxForm'),
       ),
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderHidden'),
       ),
       '#theme' => 'input__hidden',
diff --git a/core/lib/Drupal/Core/Render/Element/Item.php b/core/lib/Drupal/Core/Render/Element/Item.php
index 145b904..e6e201a 100644
--- a/core/lib/Drupal/Core/Render/Element/Item.php
+++ b/core/lib/Drupal/Core/Render/Element/Item.php
@@ -31,7 +31,7 @@ public function getInfo() {
       '#input' => TRUE,
       '#markup' => '',
       '#theme_wrappers' => array('form_element'),
-    );
+    ) + parent::getInfo();
   }
 
 }
diff --git a/core/lib/Drupal/Core/Render/Element/LanguageSelect.php b/core/lib/Drupal/Core/Render/Element/LanguageSelect.php
index 433e508..d675a19 100644
--- a/core/lib/Drupal/Core/Render/Element/LanguageSelect.php
+++ b/core/lib/Drupal/Core/Render/Element/LanguageSelect.php
@@ -23,7 +23,7 @@ public function getInfo() {
     return array(
       '#input' => TRUE,
       '#default_value' => LanguageInterface::LANGCODE_NOT_SPECIFIED,
-    );
+    ) + parent::getInfo();
   }
 
 }
diff --git a/core/lib/Drupal/Core/Render/Element/Number.php b/core/lib/Drupal/Core/Render/Element/Number.php
index 5e39541..645c23d 100644
--- a/core/lib/Drupal/Core/Render/Element/Number.php
+++ b/core/lib/Drupal/Core/Render/Element/Number.php
@@ -33,6 +33,7 @@ public function getInfo() {
         array($class, 'validateNumber'),
       ),
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderNumber'),
       ),
       '#theme' => 'input__number',
diff --git a/core/lib/Drupal/Core/Render/Element/Password.php b/core/lib/Drupal/Core/Render/Element/Password.php
index 48a20cf..b825861 100644
--- a/core/lib/Drupal/Core/Render/Element/Password.php
+++ b/core/lib/Drupal/Core/Render/Element/Password.php
@@ -30,6 +30,7 @@ public function getInfo() {
         array($class, 'processPattern'),
       ),
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderPassword'),
       ),
       '#theme' => 'input__password',
diff --git a/core/lib/Drupal/Core/Render/Element/PasswordConfirm.php b/core/lib/Drupal/Core/Render/Element/PasswordConfirm.php
index f3ea4e8..bf70223 100644
--- a/core/lib/Drupal/Core/Render/Element/PasswordConfirm.php
+++ b/core/lib/Drupal/Core/Render/Element/PasswordConfirm.php
@@ -30,7 +30,7 @@ public function getInfo() {
         array($class, 'processPasswordConfirm'),
       ),
       '#theme_wrappers' => array('form_element'),
-    );
+    ) + parent::getInfo();
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Render/Element/Radio.php b/core/lib/Drupal/Core/Render/Element/Radio.php
index f106d07..6be4fcc 100644
--- a/core/lib/Drupal/Core/Render/Element/Radio.php
+++ b/core/lib/Drupal/Core/Render/Element/Radio.php
@@ -30,6 +30,7 @@ public function getInfo() {
         array($class, 'processAjaxForm'),
       ),
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderRadio'),
       ),
       '#theme' => 'input__radio',
diff --git a/core/lib/Drupal/Core/Render/Element/Radios.php b/core/lib/Drupal/Core/Render/Element/Radios.php
index b010628..7c9db4a 100644
--- a/core/lib/Drupal/Core/Render/Element/Radios.php
+++ b/core/lib/Drupal/Core/Render/Element/Radios.php
@@ -31,11 +31,11 @@ public function getInfo() {
       '#process' => array(
         array($class, 'processRadios'),
       ),
-      '#theme_wrappers' => array('radios'),
       '#pre_render' => array(
-        array($class, 'preRenderCompositeFormElement'),
+        array($class, 'preRenderFormElement'),
       ),
-    );
+      '#theme_wrappers' => array('radios'),
+    ) + parent::getInfo();
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Render/Element/Search.php b/core/lib/Drupal/Core/Render/Element/Search.php
index dfa70ed..5e0d17a 100644
--- a/core/lib/Drupal/Core/Render/Element/Search.php
+++ b/core/lib/Drupal/Core/Render/Element/Search.php
@@ -35,6 +35,7 @@ public function getInfo() {
         array($class, 'processAjaxForm'),
       ),
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderSearch'),
       ),
       '#theme' => 'input__search',
diff --git a/core/lib/Drupal/Core/Render/Element/Select.php b/core/lib/Drupal/Core/Render/Element/Select.php
index f939641..8d10311 100644
--- a/core/lib/Drupal/Core/Render/Element/Select.php
+++ b/core/lib/Drupal/Core/Render/Element/Select.php
@@ -33,6 +33,7 @@ public function getInfo() {
         array($class, 'processAjaxForm'),
       ),
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderSelect'),
       ),
       '#theme' => 'select',
diff --git a/core/lib/Drupal/Core/Render/Element/Table.php b/core/lib/Drupal/Core/Render/Element/Table.php
index 191de68..3d0de59 100644
--- a/core/lib/Drupal/Core/Render/Element/Table.php
+++ b/core/lib/Drupal/Core/Render/Element/Table.php
@@ -53,6 +53,7 @@ public function getInfo() {
       '#tabledrag' => array(),
       // Render properties.
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderTable'),
       ),
       '#theme' => 'table',
diff --git a/core/lib/Drupal/Core/Render/Element/Tel.php b/core/lib/Drupal/Core/Render/Element/Tel.php
index 5cd4c5d..1d01b75 100644
--- a/core/lib/Drupal/Core/Render/Element/Tel.php
+++ b/core/lib/Drupal/Core/Render/Element/Tel.php
@@ -32,6 +32,7 @@ public function getInfo() {
         array($class, 'processPattern'),
       ),
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderTel'),
       ),
       '#theme' => 'input__tel',
diff --git a/core/lib/Drupal/Core/Render/Element/Textarea.php b/core/lib/Drupal/Core/Render/Element/Textarea.php
index bb5fad7..c1734bb 100644
--- a/core/lib/Drupal/Core/Render/Element/Textarea.php
+++ b/core/lib/Drupal/Core/Render/Element/Textarea.php
@@ -21,6 +21,7 @@ class Textarea extends FormElement {
    */
   public function getInfo() {
     $class = get_class($this);
+    $info = parent::getInfo();
     return array(
       '#input' => TRUE,
       '#cols' => 60,
@@ -31,6 +32,7 @@ public function getInfo() {
         array($class, 'processGroup'),
       ),
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderGroup'),
       ),
       '#theme' => 'textarea',
diff --git a/core/lib/Drupal/Core/Render/Element/Textfield.php b/core/lib/Drupal/Core/Render/Element/Textfield.php
index 4396494..aded4fe 100644
--- a/core/lib/Drupal/Core/Render/Element/Textfield.php
+++ b/core/lib/Drupal/Core/Render/Element/Textfield.php
@@ -34,6 +34,7 @@ public function getInfo() {
         array($class, 'processGroup'),
       ),
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderTextfield'),
         array($class, 'preRenderGroup'),
       ),
diff --git a/core/lib/Drupal/Core/Render/Element/Url.php b/core/lib/Drupal/Core/Render/Element/Url.php
index e891128..09df806 100644
--- a/core/lib/Drupal/Core/Render/Element/Url.php
+++ b/core/lib/Drupal/Core/Render/Element/Url.php
@@ -37,6 +37,7 @@ public function getInfo() {
         array($class, 'validateUrl'),
       ),
       '#pre_render' => array(
+        array($class, 'preRenderFormElement'),
         array($class, 'preRenderUrl'),
       ),
       '#theme' => 'input__url',
diff --git a/core/lib/Drupal/Core/Render/Element/Value.php b/core/lib/Drupal/Core/Render/Element/Value.php
index 5da3e0c..fbbfe05 100644
--- a/core/lib/Drupal/Core/Render/Element/Value.php
+++ b/core/lib/Drupal/Core/Render/Element/Value.php
@@ -24,7 +24,7 @@ class Value extends FormElement {
   public function getInfo() {
     return array(
       '#input' => TRUE,
-    );
+    ) + parent::getInfo();
   }
 
 }
diff --git a/core/lib/Drupal/Core/Render/Element/Weight.php b/core/lib/Drupal/Core/Render/Element/Weight.php
index ffcda6b..32e1f22 100644
--- a/core/lib/Drupal/Core/Render/Element/Weight.php
+++ b/core/lib/Drupal/Core/Render/Element/Weight.php
@@ -32,7 +32,7 @@ public function getInfo() {
         array($class, 'processWeight'),
         array($class, 'processAjaxForm'),
       ),
-    );
+    ) + parent::getInfo();
   }
 
   /**
diff --git a/core/modules/field_ui/src/Tests/FieldUiTestBase.php b/core/modules/field_ui/src/Tests/FieldUiTestBase.php
index 6157893..421500c 100644
--- a/core/modules/field_ui/src/Tests/FieldUiTestBase.php
+++ b/core/modules/field_ui/src/Tests/FieldUiTestBase.php
@@ -78,6 +78,7 @@ function fieldUIAddNewField($bundle_path, $initial_edit, $field_edit = array(),
 
     // Second step : 'Field settings' form.
     $this->drupalPostForm(NULL, $field_edit, t('Save field settings'));
+    $this->assertNoRaw('<', 'The page does not have double escaped HTML tags.');
     $this->assertRaw(t('Updated field %label field settings.', array('%label' => $label)), 'Redirected to instance and widget settings page.');
 
     // Third step : 'Instance settings' form.
@@ -105,6 +106,7 @@ function fieldUIAddExistingField($bundle_path, $initial_edit, $instance_edit = a
 
     // First step : 'Re-use existing field' on the 'Manage fields' page.
     $this->drupalPostForm("$bundle_path/fields", $initial_edit, t('Save'));
+    $this->assertNoRaw('<', 'The page does not have double escaped HTML tags.');
 
     // Second step : 'Instance settings' form.
     $this->drupalPostForm(NULL, $instance_edit, t('Save settings'));
diff --git a/core/modules/field_ui/src/Tests/ManageFieldsTest.php b/core/modules/field_ui/src/Tests/ManageFieldsTest.php
index c137308..201f5f6 100644
--- a/core/modules/field_ui/src/Tests/ManageFieldsTest.php
+++ b/core/modules/field_ui/src/Tests/ManageFieldsTest.php
@@ -141,6 +141,7 @@ function updateField() {
 
     // Go to the field instance edit page.
     $this->drupalGet('admin/structure/types/manage/' . $this->type . '/fields/' . $instance_id);
+    $this->assertNoRaw('<', 'The page does not have double escaped HTML tags.');
     $edit = array(
       'instance[settings][test_instance_setting]' => $string,
     );
@@ -221,6 +222,7 @@ protected function deleteFieldInstance() {
     // Delete the field instance.
     $instance_id = 'node.' . $this->type . '.' . $this->field_name;
     $this->drupalGet('admin/structure/types/manage/' . $this->type . '/fields/' . $instance_id);
+    $this->assertNoRaw('<', 'The page does not have double escaped HTML tags.');
     $this->drupalPostForm(NULL, array(), t('Delete field'));
     $this->assertResponse(200);
   }
@@ -564,6 +566,9 @@ function testHelpDescriptions() {
 
     entity_get_form_display('node', 'article', 'default')->setComponent('field_image')->save();
 
+    $this->drupalGet('admin/structure/types/manage/article/fields/node.article.field_image');
+    $this->assertNoRaw('<div', 'Image fields do not have double escaped HTML tags.');
+
     $edit = array(
       'instance[description]' => '<strong>Test with an upload field.',
     );
diff --git a/core/modules/locale/src/Form/ImportForm.php b/core/modules/locale/src/Form/ImportForm.php
index 426187f..75dda76 100644
--- a/core/modules/locale/src/Form/ImportForm.php
+++ b/core/modules/locale/src/Form/ImportForm.php
@@ -103,18 +103,22 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       'file_validate_extensions' => array('po'),
       'file_validate_size' => array(file_upload_max_size()),
     );
+
+    $file_description = array(
+      '#theme' => 'file_upload_help',
+      '#description' => $this->t('A Gettext Portable Object file.'),
+      '#upload_validators' => $validators,
+    );
+
     $form['file'] = array(
       '#type' => 'file',
       '#title' => $this->t('Translation file'),
-      '#description' => array(
-        '#theme' => 'file_upload_help',
-        '#description' => $this->t('A Gettext Portable Object file.'),
-        '#upload_validators' => $validators,
-      ),
+      '#description' => drupal_render($file_description),
       '#size' => 50,
       '#upload_validators' => $validators,
       '#attributes' => array('class' => array('file-import-input')),
     );
+
     $form['langcode'] = array(
       '#type' => 'select',
       '#title' => $this->t('Language'),
diff --git a/core/modules/options/src/Tests/OptionsFieldUITest.php b/core/modules/options/src/Tests/OptionsFieldUITest.php
index ebbba4b..70bf9d4 100644
--- a/core/modules/options/src/Tests/OptionsFieldUITest.php
+++ b/core/modules/options/src/Tests/OptionsFieldUITest.php
@@ -278,6 +278,7 @@ protected function createOptionsField($type) {
   function assertAllowedValuesInput($input_string, $result, $message) {
     $edit = array('field[settings][allowed_values]' => $input_string);
     $this->drupalPostForm($this->admin_path, $edit, t('Save field settings'));
+    $this->assertNoRaw('&amp;lt;', 'The page does not have double escaped HTML tags.');
 
     if (is_string($result)) {
       $this->assertText($result, $message);