diff --git a/core/lib/Drupal/Core/Extension/module.api.php b/core/lib/Drupal/Core/Extension/module.api.php
index af77c19..3c1c228 100644
--- a/core/lib/Drupal/Core/Extension/module.api.php
+++ b/core/lib/Drupal/Core/Extension/module.api.php
@@ -700,21 +700,27 @@ function hook_post_update_NAME(&$sandbox) {
 
   $result = t('Node %nid saved', ['%nid' => $node->id()]);
 
-  // Example of updating an existing configuration entity.
-  // This example disables the frontpage view.
-  $view = \Drupal\views\Entity\View::load('frontpage');
-  $view->setStatus(FALSE);
-  $view->save();
-
-  // Example of a usecase where some values of views plugins changes.
-  $view = \Drupal\views\Entity\View::load('frontpage');
-  $display = &$view->getDisplay('default');
-  // In this example we convert from %1 tokens to twig tokens, see
-  // https://www.drupal.org/node/2492839
-  $display['display_options']['title'] = str_replace('%1', '{{ arguments.1 }}', $display['display_options']['title']);
-  $view->save();
-
-  $result .= t('View %view_id saved', [$view->id()]);
+  // Example of disabling blocks with missing condition contexts. Note: The
+  // block itself is in a state which is valid at that point.
+  // @see block_update_8001()
+  // @see block_post_update_disable_blocks_with_missing_contexts()
+  $block_update_8001 = \Drupal::keyValue('update_backup')->get('block_update_8001', []);
+
+  $block_ids = array_keys($block_update_8001);
+  $block_storage = \Drupal::entityManager()->getStorage('block');
+  $blocks = $block_storage->loadMultiple($block_ids);
+  /** @var $blocks \Drupal\block\BlockInterface[] */
+  foreach ($blocks as $block) {
+    // This block will have an invalid context mapping service and must be
+    // disabled in order to prevent information disclosure.
+
+    // Disable currently enabled blocks.
+    if ($block_update_8001[$block->id()]['status']) {
+      $block->setStatus(FALSE);
+      $block->save();
+    }
+  }
+
   return $result;
 }