diff --git a/core/core.services.yml b/core/core.services.yml
index 3f68677200..0d5ea4a312 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -1672,7 +1672,7 @@ services:
       - { name: event_subscriber }
   messenger:
     class: Drupal\Core\Messenger\Messenger
-    arguments: ['@session.flash_bag', '@page_cache_kill_switch']
+    arguments: ['@session', '@page_cache_kill_switch']
   tempstore.private:
     class: Drupal\Core\TempStore\PrivateTempStoreFactory
     arguments: ['@keyvalue.expirable', '@lock', '@current_user', '@request_stack', '%tempstore.expire%']
diff --git a/core/lib/Drupal/Core/Installer/InstallerServiceProvider.php b/core/lib/Drupal/Core/Installer/InstallerServiceProvider.php
index dd4ae5f470..3af9d99a79 100644
--- a/core/lib/Drupal/Core/Installer/InstallerServiceProvider.php
+++ b/core/lib/Drupal/Core/Installer/InstallerServiceProvider.php
@@ -60,6 +60,13 @@ public function register(ContainerBuilder $container) {
       // we don't need to ship with a custom proxy class.
       ->setLazy(FALSE);
 
+    // Replace the session_manager with an implementation that does not use the
+    // database.
+    $container->getDefinition('session_manager')
+      ->setClass('Symfony\Component\HttpFoundation\Session\Storage\NativeSessionStorage')
+      ->setArguments([])
+      ->setMethodCalls([]);
+
     // Use a performance optimised module extension list.
     $container->getDefinition('extension.list.module')->setClass('Drupal\Core\Installer\InstallerModuleExtensionList');
   }
diff --git a/core/lib/Drupal/Core/Messenger/Messenger.php b/core/lib/Drupal/Core/Messenger/Messenger.php
index c0949438cc..d71f1719e0 100644
--- a/core/lib/Drupal/Core/Messenger/Messenger.php
+++ b/core/lib/Drupal/Core/Messenger/Messenger.php
@@ -5,7 +5,7 @@
 use Drupal\Component\Render\MarkupInterface;
 use Drupal\Core\PageCache\ResponsePolicy\KillSwitch;
 use Drupal\Core\Render\Markup;
-use Symfony\Component\HttpFoundation\Session\Flash\FlashBagInterface;
+use Symfony\Component\HttpFoundation\Session\SessionInterface;
 
 /**
  * The messenger service.
@@ -13,11 +13,11 @@
 class Messenger implements MessengerInterface {
 
   /**
-   * The flash bag.
+   * The session.
    *
-   * @var \Symfony\Component\HttpFoundation\Session\Flash\FlashBagInterface
+   * @var \Symfony\Component\HttpFoundation\Session\SessionInterface
    */
-  protected $flashBag;
+  protected $session;
 
   /**
    * The kill switch.
@@ -29,16 +29,26 @@ class Messenger implements MessengerInterface {
   /**
    * Messenger constructor.
    *
-   * @param \Symfony\Component\HttpFoundation\Session\Flash\FlashBagInterface $flash_bag
-   *   The flash bag.
+   * @param \Symfony\Component\HttpFoundation\Session\SessionInterface $session
+   *   The session.
    * @param \Drupal\Core\PageCache\ResponsePolicy\KillSwitch $killSwitch
    *   The kill switch.
    */
-  public function __construct(FlashBagInterface $flash_bag, KillSwitch $killSwitch) {
-    $this->flashBag = $flash_bag;
+  public function __construct(SessionInterface $session, KillSwitch $killSwitch) {
+    $this->session = $session;
     $this->killSwitch = $killSwitch;
   }
 
+  /**
+   * Gets the flash bag.
+   *
+   * @return \Symfony\Component\HttpFoundation\Session\Flash\FlashBagInterface
+   *   The flash bag.
+   */
+  protected function getFlashBag() {
+    return $this->session->getFlashBag();
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -56,8 +66,8 @@ public function addMessage($message, $type = self::TYPE_STATUS, $repeat = FALSE)
 
     // Do not use strict type checking so that equivalent string and
     // MarkupInterface objects are detected.
-    if ($repeat || !in_array($message, $this->flashBag->peek($type))) {
-      $this->flashBag->add($type, $message);
+    if ($repeat || !in_array($message, $this->getFlashBag()->peek($type))) {
+      $this->getFlashBag()->add($type, $message);
     }
 
     // Mark this page as being uncacheable.
@@ -84,29 +94,41 @@ public function addWarning($message, $repeat = FALSE) {
    * {@inheritdoc}
    */
   public function all() {
-    return $this->flashBag->peekAll();
+    if (!$this->session->isStarted()) {
+      return [];
+    }
+    return $this->getFlashBag()->peekAll();
   }
 
   /**
    * {@inheritdoc}
    */
   public function deleteAll() {
-    return $this->flashBag->clear();
+    if (!$this->session->isStarted()) {
+      return [];
+    }
+    return $this->getFlashBag()->clear();
   }
 
   /**
    * {@inheritdoc}
    */
   public function deleteByType($type) {
+    if (!$this->session->isStarted()) {
+      return [];
+    }
     // Flash bag gets and clears flash messages from the stack.
-    return $this->flashBag->get($type);
+    return $this->getFlashBag()->get($type);
   }
 
   /**
    * {@inheritdoc}
    */
   public function messagesByType($type) {
-    return $this->flashBag->peek($type);
+    if (!$this->session->isStarted()) {
+      return [];
+    }
+    return $this->getFlashBag()->peek($type);
   }
 
 }
diff --git a/core/lib/Drupal/Core/Session/SessionManager.php b/core/lib/Drupal/Core/Session/SessionManager.php
index 607103109d..f87435c56d 100644
--- a/core/lib/Drupal/Core/Session/SessionManager.php
+++ b/core/lib/Drupal/Core/Session/SessionManager.php
@@ -5,6 +5,7 @@
 use Drupal\Component\Utility\Crypt;
 use Drupal\Core\Database\Connection;
 use Drupal\Core\DependencyInjection\DependencySerializationTrait;
+use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\RequestStack;
 use Symfony\Component\HttpFoundation\Session\Storage\NativeSessionStorage;
 
@@ -108,6 +109,11 @@ public function start() {
     }
 
     $request = $this->requestStack->getCurrentRequest();
+    // If a session is started prior to the the request stack having the request
+    // create one from globals.
+    if (!$request) {
+      $request = Request::createFromGlobals();
+    }
     $this->setOptions($this->sessionConfiguration->getOptions($request));
 
     if ($this->sessionConfiguration->hasSession($request)) {