From 76bb51117423afc67fb10412201b6715d7ffd68b Mon Sep 17 00:00:00 2001
From: Alex Pott <alex.a.pott@googlemail.com>
Date: Thu, 6 Dec 2018 11:34:43 +0100
Subject: [PATCH] Issue #3017753 by mxr576, alexpott: MemoryBackend should
 validate the passed cids

---
 core/lib/Drupal/Core/Cache/MemoryBackend.php | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/core/lib/Drupal/Core/Cache/MemoryBackend.php b/core/lib/Drupal/Core/Cache/MemoryBackend.php
index 09454d78505f..c1276923754b 100644
--- a/core/lib/Drupal/Core/Cache/MemoryBackend.php
+++ b/core/lib/Drupal/Core/Cache/MemoryBackend.php
@@ -156,7 +156,8 @@ class MemoryBackend implements CacheBackendInterface, CacheTagsInvalidatorInterf
    * {@inheritdoc}
    */
   public function invalidateMultiple(array $cids) {
-    foreach ($cids as $cid) {
+    $items = array_intersect_key($this->cache, array_flip($cids));
+    foreach ($items as $cid => $item) {
       $this->cache[$cid]->expire = $this->getRequestTime() - 1;
     }
   }