diff --git a/.travis.yml b/.travis.yml
index 4ebaeafaf..4124bdb7d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -37,6 +37,7 @@ matrix:
         - DB=PGSQL
         - PHPUNIT_TEST=framework
     - php: 7.1
+      if: type IN (cron)
       env:
         - DB=MYSQL
         - PDO=1
diff --git a/README.md b/README.md
index 9b5d4834e..3ee61ab8e 100644
--- a/README.md
+++ b/README.md
@@ -8,29 +8,28 @@
 [![License](https://poser.pugx.org/silverstripe/framework/license.svg)](https://github.com/silverstripe/silverstripe-framework#license)
 [![Dependency Status](https://www.versioneye.com/php/silverstripe:framework/badge.svg)](https://www.versioneye.com/php/silverstripe:framework)
 [![Reference Status](https://www.versioneye.com/php/silverstripe:framework/reference_badge.svg?style=flat)](https://www.versioneye.com/php/silverstripe:framework/references)
-![helpfulrobot](https://helpfulrobot.io/silverstripe/framework/badge)
 
-PHP5 framework forming the base for the SilverStripe CMS ([http://silverstripe.org](http://silverstripe.org)).
-Requires a [`silverstripe-installer`](http://github.com/silverstripe/silverstripe-installer) base project. Typically used alongside the [`cms`](http://github.com/silverstripe/silverstripe-cms) module.
+PHP framework forming the base for the SilverStripe CMS ([https://silverstripe.org](https://silverstripe.org)). 
+Requires a [`silverstripe-installer`](https://github.com/silverstripe/silverstripe-installer) base project. Typically used alongside the [`cms`](https://github.com/silverstripe/silverstripe-cms) module.
 
 ## Installation ##
 
-See [installation on different platforms](http://doc.silverstripe.org/framework/en/installation/),
-and [installation from source](http://doc.silverstripe.org/framework/en/installation/from-source).
+See [installation on different platforms](https://doc.silverstripe.org/framework/en/installation/),
+and [installation from source](https://doc.silverstripe.org/framework/en/installation/from-source).
 
 ## Bugtracker ##
 
-Bugs are tracked on [github.com](https://github.com/silverstripe/silverstripe-framework/issues).
-Please read our [issue reporting guidelines](http://doc.silverstripe.org/framework/en/misc/contributing/issues).
+Bugs are tracked on [github.com](https://github.com/silverstripe/silverstripe-framework/issues). 
+Please read our [issue reporting guidelines](https://doc.silverstripe.org/framework/en/misc/contributing/issues).
 
 ## Development and Contribution ##
 
-If you would like to make changes to the SilverStripe core codebase, we have an extensive [guide to contributing code](http://doc.silverstripe.org/framework/en/misc/contributing/code).
+If you would like to make changes to the SilverStripe core codebase, we have an extensive [guide to contributing code](https://docs.silverstripe.org/en/contributing/code/).
 
 ## Links ##
 
- * [Server Requirements](http://doc.silverstripe.org/framework/en/installation/server-requirements)
- * [Changelogs](http://doc.silverstripe.org/framework/en/changelogs/)
+ * [Server Requirements](https://doc.silverstripe.org/framework/en/installation/server-requirements)
+ * [Changelogs](https://doc.silverstripe.org/framework/en/changelogs/)
  * [Bugtracker: Framework](https://github.com/silverstripe/silverstripe-framework/issues)
  * [Bugtracker: CMS](https://github.com/silverstripe/silverstripe-cms/issues)
  * [Bugtracker: Installer](https://github.com/silverstripe/silverstripe-installer/issues)
diff --git a/docs/en/02_Developer_Guides/01_Templates/06_Themes.md b/docs/en/02_Developer_Guides/01_Templates/06_Themes.md
index c60a33ca9..c4d68caf3 100644
--- a/docs/en/02_Developer_Guides/01_Templates/06_Themes.md
+++ b/docs/en/02_Developer_Guides/01_Templates/06_Themes.md
@@ -32,8 +32,7 @@ As you've added new files to your SilverStripe installation, make sure you clear
 ### Configuring themes
 
 After installing the files through either method, update the current theme in SilverStripe. This can be done by 
-either altering the `SSViewer.themes` setting in a [config.yml](../configuration) or by changing the current theme in 
-the Site Configuration panel (http://yoursite.com/admin/settings)
+altering the `SSViewer.themes` setting in a [config.yml](../configuration)
 
 **mysite/_config/app.yml**
 
@@ -105,4 +104,4 @@ The final step is to [submit your theme to Packagist](https://packagist.org/abou
 
 ## Related Lessons
 * [Creating your first theme](https://www.silverstripe.org/learn/lessons/v4/creating-your-first-theme-1)
-* [Migrating static templates into your theme](https://www.silverstripe.org/learn/lessons/v4/migrating-static-templates-into-your-theme-1)
\ No newline at end of file
+* [Migrating static templates into your theme](https://www.silverstripe.org/learn/lessons/v4/migrating-static-templates-into-your-theme-1)
diff --git a/docs/en/04_Changelogs/3.5.8.md b/docs/en/04_Changelogs/3.5.8.md
new file mode 100644
index 000000000..39c54a5d5
--- /dev/null
+++ b/docs/en/04_Changelogs/3.5.8.md
@@ -0,0 +1,9 @@
+# 3.5.8
+
+<!--- Changes below this line will be automatically regenerated -->
+
+## Change Log
+
+### Security
+
+ * 2018-04-11 [577138882](https://github.com/silverstripe/silverstripe-framework/commit/577138882) Restrict non-admins from being assigned to admin groups (Damian Mooyman) - See [ss-2018-001](http://www.silverstripe.org/download/security-releases/ss-2018-001)
diff --git a/docs/en/04_Changelogs/3.6.6.md b/docs/en/04_Changelogs/3.6.6.md
new file mode 100644
index 000000000..d85ed86cc
--- /dev/null
+++ b/docs/en/04_Changelogs/3.6.6.md
@@ -0,0 +1,17 @@
+# 3.6.6
+
+This security release removes the following file extensions from the default whitelist of accepted types for 
+uploaded files: `dotm`, `potm`, `jar`, `css`, `js` and `xltm`.
+
+If you require the ability to upload these file types in your projects, you will need to add them back in again.
+For more information, see ["Limit the allowed file types"](https://docs.silverstripe.org/en/3/developer_guides/forms/field_types/uploadfield/#limit-the-allowed-filetypes).
+
+<!--- Changes below this line will be automatically regenerated -->
+
+## Change Log
+
+### Security
+
+ * 2018-05-08 [19fdebfa2](https://github.com/silverstripe/silverstripe-framework/commit/19fdebfa2) Remove dotm, potm, jar, css, js, xltm from default File.allowed_extensions (Robbie Averill) - See [ss-2018-014](http://www.silverstripe.org/download/security-releases/ss-2018-014)
+ * 2018-04-11 [577138882](https://github.com/silverstripe/silverstripe-framework/commit/577138882) Restrict non-admins from being assigned to admin groups (Damian Mooyman) - See [ss-2018-001](http://www.silverstripe.org/download/security-releases/ss-2018-001)
+ 
diff --git a/docs/en/04_Changelogs/rc/3.5.8-rc1.md b/docs/en/04_Changelogs/rc/3.5.8-rc1.md
new file mode 100644
index 000000000..c19407a63
--- /dev/null
+++ b/docs/en/04_Changelogs/rc/3.5.8-rc1.md
@@ -0,0 +1,9 @@
+# 3.5.8-rc1
+
+<!--- Changes below this line will be automatically regenerated -->
+
+## Change Log
+
+### Security
+
+ * 2018-04-11 [577138882]() Restrict non-admins from being assigned to admin groups (Damian Mooyman) - See [ss-2018-001](http://www.silverstripe.org/download/security-releases/ss-2018-001)
diff --git a/docs/en/04_Changelogs/rc/3.6.6-rc1.md b/docs/en/04_Changelogs/rc/3.6.6-rc1.md
new file mode 100644
index 000000000..2d4bf0b66
--- /dev/null
+++ b/docs/en/04_Changelogs/rc/3.6.6-rc1.md
@@ -0,0 +1,16 @@
+# 3.6.6-rc1
+
+This security release removes the following file extensions from the default whitelist of accepted types for 
+uploaded files: `dotm`, `potm`, `jar`, `css`, `js` and `xltm`.
+
+If you require the ability to upload these file types in your projects, you will need to add them back in again.
+For more information, see ["Limit the allowed file types"](https://docs.silverstripe.org/en/3/developer_guides/forms/field_types/uploadfield/#limit-the-allowed-filetypes).
+
+<!--- Changes below this line will be automatically regenerated -->
+
+## Change Log
+
+### Security
+
+ * 2018-05-08 [19fdebfa2]() Remove dotm, potm, jar, css, js, xltm from default File.allowed_extensions (Robbie Averill) - See [ss-2018-014](http://www.silverstripe.org/download/security-releases/ss-2018-014)
+ * 2018-04-11 [577138882]() Restrict non-admins from being assigned to admin groups (Damian Mooyman) - See [ss-2018-001](http://www.silverstripe.org/download/security-releases/ss-2018-001)
diff --git a/src/Dev/DevelopmentAdmin.php b/src/Dev/DevelopmentAdmin.php
index 267d3386a..734e980ce 100644
--- a/src/Dev/DevelopmentAdmin.php
+++ b/src/Dev/DevelopmentAdmin.php
@@ -132,7 +132,7 @@ class DevelopmentAdmin extends Controller
             // in CLI we cant use httpError because of a bug with stuff being in the output already, see DevAdminControllerTest
             throw new Exception($msg);
         } else {
-            $this->httpError(500, $msg);
+            $this->httpError(404, $msg);
         }
     }
 
diff --git a/src/Forms/FieldList.php b/src/Forms/FieldList.php
index 2072a5dca..df09f5995 100644
--- a/src/Forms/FieldList.php
+++ b/src/Forms/FieldList.php
@@ -257,8 +257,7 @@ class FieldList extends ArrayList
      * This is most commonly used when overloading getCMSFields()
      *
      * @param string $tabName The name of the tab or tabset.  Subtabs can be referred to as TabSet.Tab
-     *                        or TabSet.Tab.Subtab.
-     * This function will create any missing tabs.
+     *                        or TabSet.Tab.Subtab. This function will create any missing tabs.
      * @param array $fields An array of {@link FormField} objects.
      * @param string $insertBefore Name of field to insert before
      *
diff --git a/src/Forms/GridField/GridFieldFooter.php b/src/Forms/GridField/GridFieldFooter.php
index a49180068..1dcc8767a 100644
--- a/src/Forms/GridField/GridFieldFooter.php
+++ b/src/Forms/GridField/GridFieldFooter.php
@@ -38,7 +38,7 @@ class GridFieldFooter implements GridField_HTMLProvider
     /**
      *
      * @param string $message A message to display in the footer
-     * @param bool $showrecordcount
+     * @param boolt $showrecordcount
      */
     public function __construct($message = null, $showrecordcount = true)
     {
diff --git a/src/Forms/GridField/GridState.php b/src/Forms/GridField/GridState.php
index b6d30d019..17368d22a 100644
--- a/src/Forms/GridField/GridState.php
+++ b/src/Forms/GridField/GridState.php
@@ -29,7 +29,7 @@ class GridState extends HiddenField
 
     /**
      * @param GridField $grid
-     * @param string $value json encoded string
+     * @param string $value JSON encoded string
      */
     public function __construct($grid, $value = null)
     {
diff --git a/src/Forms/HTMLEditor/HTMLEditorSanitiser.php b/src/Forms/HTMLEditor/HTMLEditorSanitiser.php
index 4aee787f3..ca4e5f407 100644
--- a/src/Forms/HTMLEditor/HTMLEditorSanitiser.php
+++ b/src/Forms/HTMLEditor/HTMLEditorSanitiser.php
@@ -190,7 +190,7 @@ class HTMLEditorSanitiser
     /**
      * Given an attribute name, return the rule structure for that attribute
      *
-     * @param stdClass $elementRule
+     * @param object $elementRule
      * @param string $name The attribute name
      * @return stdClass The attribute rule
      */
@@ -211,7 +211,7 @@ class HTMLEditorSanitiser
      * Given a DOMElement and an element rule, check if that element passes the rule
      * @param DOMElement $element The element to check
      * @param stdClass $rule The rule to check against
-     * @return bool true if the element passes (and so can be kept), false if it fails (and so needs stripping)
+     * @return bool True if the element passes (and so can be kept), false if it fails (and so needs stripping)
      */
     protected function elementMatchesRule($element, $rule = null)
     {
diff --git a/src/Forms/TreeDropdownField.php b/src/Forms/TreeDropdownField.php
index 02c5f1f88..f96379c75 100644
--- a/src/Forms/TreeDropdownField.php
+++ b/src/Forms/TreeDropdownField.php
@@ -654,7 +654,7 @@ class TreeDropdownField extends FormField
     }
 
     /**
-     * @return String
+     * @return string
      */
     public function getKeyField()
     {
diff --git a/src/Forms/UploadReceiver.php b/src/Forms/UploadReceiver.php
index 8f1e9d209..1270819ce 100644
--- a/src/Forms/UploadReceiver.php
+++ b/src/Forms/UploadReceiver.php
@@ -131,7 +131,7 @@ trait UploadReceiver
      * Set custom validator for this field
      *
      * @param Upload_Validator $validator
-     * @return $this Self reference
+     * @return $this
      */
     public function setValidator(Upload_Validator $validator)
     {
@@ -143,7 +143,7 @@ trait UploadReceiver
      * Sets the upload folder name
      *
      * @param string $folderName
-     * @return $this Self reference
+     * @return $this
      */
     public function setFolderName($folderName)
     {
diff --git a/src/ORM/ArrayLib.php b/src/ORM/ArrayLib.php
index d47bc073b..5f83be629 100644
--- a/src/ORM/ArrayLib.php
+++ b/src/ORM/ArrayLib.php
@@ -247,6 +247,7 @@ class ArrayLib
      * @param array $array
      * @param boolean $preserveKeys
      * @param array $out
+     *
      * @return array
      */
     public static function flatten($array, $preserveKeys = true, &$out = array())
diff --git a/src/ORM/DataObject.php b/src/ORM/DataObject.php
index 8a8069bf1..c6356fe43 100644
--- a/src/ORM/DataObject.php
+++ b/src/ORM/DataObject.php
@@ -531,7 +531,13 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
         // Copy all components from source to destination
         $source = $sourceObject->getManyManyComponents($relation);
         $dest = $destinationObject->getManyManyComponents($relation);
-        $extraFieldNames = $source->getExtraFields();
+
+        if ($source instanceof ManyManyList) {
+            $extraFieldNames = $source->getExtraFields();
+        } else {
+            $extraFieldNames = [];
+        }
+
         foreach ($source as $item) {
             // Merge extra fields
             $extraFields = [];
diff --git a/src/Security/Member.php b/src/Security/Member.php
index 29cc3bc44..164f995ee 100644
--- a/src/Security/Member.php
+++ b/src/Security/Member.php
@@ -1360,6 +1360,11 @@ class Member extends DataObject
      */
     public static function mapInCMSGroups($groups = null)
     {
+        // non-countable $groups will issue a warning when using count() in PHP 7.2+
+        if (!$groups) {
+            $groups = [];
+        }
+
         // Check CMS module exists
         if (!class_exists(LeftAndMain::class)) {
             return ArrayList::create()->map();
diff --git a/tests/php/ORM/DataObjectDuplicationTest.php b/tests/php/ORM/DataObjectDuplicationTest.php
index 48b3fbf38..8ef741805 100644
--- a/tests/php/ORM/DataObjectDuplicationTest.php
+++ b/tests/php/ORM/DataObjectDuplicationTest.php
@@ -38,6 +38,7 @@ class DataObjectDuplicationTest extends SapphireTest
         // Check 'bobcats' relation duplicated
         $twoOne = $this->objFromFixture(DataObjectDuplicationTest\Bobcat::class, 'one');
         $twoTwo = $this->objFromFixture(DataObjectDuplicationTest\Bobcat::class, 'two');
+
         $this->assertListEquals(
             [
                 ['Title' => 'Bobcat two'],