diff --git a/core/lib/Drupal/Core/Database/Connection.php b/core/lib/Drupal/Core/Database/Connection.php
index 7cbe167..e0c1714 100644
--- a/core/lib/Drupal/Core/Database/Connection.php
+++ b/core/lib/Drupal/Core/Database/Connection.php
@@ -596,7 +596,7 @@ protected function expandArguments(&$query, &$args) {
     // to expand it out into a comma-delimited set of placeholders.
     foreach (array_filter($args, 'is_array') as $key => $data) {
       $new_keys = array();
-      foreach ($data as $i => $value) {
+      foreach (array_values($data) as $i => $value) {
         // This assumes that there are no other placeholders that use the same
         // name.  For example, if the array placeholder is defined as :example
         // and there is already an :example_2 placeholder, this will generate
diff --git a/core/modules/system/src/Tests/Database/QueryTest.php b/core/modules/system/src/Tests/Database/QueryTest.php
index ddfd1a5..6db2a5a 100644
--- a/core/modules/system/src/Tests/Database/QueryTest.php
+++ b/core/modules/system/src/Tests/Database/QueryTest.php
@@ -7,6 +7,8 @@
 
 namespace Drupal\system\Tests\Database;
 
+use Drupal\Core\Database\DatabaseExceptionWrapper;
+
 /**
  * Tests Drupal's extended prepared statement syntax..
  *
@@ -21,4 +23,31 @@ function testArraySubstitution() {
 
     $this->assertEqual(count($names), 3, 'Correct number of names returned');
   }
+
+  /**
+   * Tests SQL injection via database query array arguments.
+   */
+  function testArrayArgumentsSQLInjection() {
+    // Attempt SQL injection and verify that it does not work.
+    $condition = array(
+      "1 ;INSERT INTO {test} SET name = 'test12345678'; -- " => '',
+      '1' => '',
+    );
+    try {
+      db_query("SELECT * FROM {test} WHERE name = :name", array(':name' => $condition))->fetchObject();
+      $this->fail('SQL injection attempt via array arguments should result in a database exception.');
+    }
+    catch (DatabaseExceptionWrapper $e) {
+      $this->pass('SQL injection attempt via array arguments should result in a database exception.');
+    }
+
+    // Test that the insert query that was used in the SQL injection attempt
+    // did not result in a row being inserted in the database.
+    $result = db_select('test')
+      ->condition('name', 'test12345678')
+      ->countQuery()
+      ->execute()
+      ->fetchField();
+    $this->assertFalse($result, 'SQL injection attempt did not result in a row being inserted in the database table.');
+  }
 }