diff --git a/src/Control/Cookie.php b/src/Control/Cookie.php
index aafefb82b..2995e844f 100644
--- a/src/Control/Cookie.php
+++ b/src/Control/Cookie.php
@@ -14,6 +14,12 @@ class Cookie
 {
     use Configurable;
 
+    public const SAMESITE_LAX = 'Lax';
+
+    public const SAMESITE_STRICT = 'Strict';
+
+    public const SAMESITE_NONE = 'None';
+
     /**
      * @config
      *
@@ -25,7 +31,7 @@ class Cookie
      * Must be "Strict", "Lax", or "None"
      * @config
      */
-    private static string $default_samesite = 'Lax';
+    private static string $default_samesite = self::SAMESITE_LAX;
 
     /**
      * Fetch the current instance of the cookie backend.
@@ -110,14 +116,14 @@ class Cookie
     public static function validateSameSite(string $sameSite): void
     {
         $validValues = [
-            'Strict',
-            'Lax',
-            'None',
+            self::SAMESITE_STRICT,
+            self::SAMESITE_LAX,
+            self::SAMESITE_NONE,
         ];
         if (!in_array($sameSite, $validValues)) {
             throw new LogicException('Cookie samesite must be "Strict", "Lax", or "None"');
         }
-        if ($sameSite === 'None' && !Director::is_https(self::getRequest())) {
+        if ($sameSite === self::SAMESITE_NONE && !Director::is_https(self::getRequest())) {
             Injector::inst()->get(LoggerInterface::class)->warning('Cookie samesite cannot be "None" for non-https requests.');
         }
     }
diff --git a/src/Control/CookieJar.php b/src/Control/CookieJar.php
index 6c3b0a26c..df85e232e 100644
--- a/src/Control/CookieJar.php
+++ b/src/Control/CookieJar.php
@@ -204,8 +204,8 @@ class CookieJar implements Cookie_Backend
     private function getSameSite(string $name): string
     {
         if ($name === session_name()) {
-            return Session::config()->get('cookie_samesite');
+            return Session::config()->get('cookie_samesite') ?? Cookie::SAMESITE_LAX;
         }
-        return Cookie::config()->get('default_samesite');
+        return Cookie::config()->get('default_samesite') ?? Cookie::SAMESITE_LAX;
     }
 }
diff --git a/src/Control/Director.php b/src/Control/Director.php
index 3ac23350e..8c3a0f8f2 100644
--- a/src/Control/Director.php
+++ b/src/Control/Director.php
@@ -825,10 +825,11 @@ class Director implements TemplateGlobalProvider
         return (
             // Base check for existence of a host on a compliant URL
             parse_url($url ?? '', PHP_URL_HOST)
-            // Check for more than one leading slash without a protocol.
+            // Check for more than one leading slash (forward or backward) without a protocol.
             // While not a RFC compliant absolute URL, it is completed to a valid URL by some browsers,
             // and hence a potential security risk. Single leading slashes are not an issue though.
-            || preg_match('%^\s*/{2,}%', $url ?? '')
+            // Note: Need 4 backslashes to have a single non-escaped backslash for regex.
+            || preg_match('%^\s*(\\\\|/){2,}%', $url ?? '')
             || (
                 // If a colon is found, check if it's part of a valid scheme definition
                 // (meaning its not preceded by a slash).
diff --git a/src/Control/Session.php b/src/Control/Session.php
index 5d49b92b3..c083f77ad 100644
--- a/src/Control/Session.php
+++ b/src/Control/Session.php
@@ -139,7 +139,7 @@ class Session
      * Must be "Strict", "Lax", or "None".
      * @config
      */
-    private static string $cookie_samesite = 'Lax';
+    private static string $cookie_samesite = Cookie::SAMESITE_LAX;
 
     /**
      * Name of session cache limiter to use.
@@ -374,7 +374,7 @@ class Session
             }
         }
 
-        $sameSite = static::config()->get('cookie_samesite');
+        $sameSite = static::config()->get('cookie_samesite') ?? Cookie::SAMESITE_LAX;
         Cookie::validateSameSite($sameSite);
         $secure = $this->isCookieSecure($sameSite, Director::is_https($request));
 
diff --git a/src/Forms/GridField/GridFieldPrintButton.php b/src/Forms/GridField/GridFieldPrintButton.php
index 1ec2be669..1fc965808 100644
--- a/src/Forms/GridField/GridFieldPrintButton.php
+++ b/src/Forms/GridField/GridFieldPrintButton.php
@@ -228,21 +228,23 @@ class GridFieldPrintButton extends AbstractGridFieldComponent implements GridFie
 
         /** @var DataObject $item */
         foreach ($items->limit(null) as $item) {
-            $itemRow = new ArrayList();
+            if (!$item->hasMethod('canView') || $item->canView()) {
+                $itemRow = new ArrayList();
 
-            foreach ($printColumns as $field => $label) {
-                $value = $gridFieldColumnsComponent
-                    ? strip_tags($gridFieldColumnsComponent->getColumnContent($gridField, $item, $field))
-                    : $gridField->getDataFieldValue($item, $field);
+                foreach ($printColumns as $field => $label) {
+                    $value = $gridFieldColumnsComponent
+                        ? strip_tags($gridFieldColumnsComponent->getColumnContent($gridField, $item, $field))
+                        : $gridField->getDataFieldValue($item, $field);
 
-                $itemRow->push(new ArrayData([
-                    "CellString" => $value,
+                    $itemRow->push(new ArrayData([
+                        "CellString" => $value,
+                    ]));
+                }
+
+                $itemRows->push(new ArrayData([
+                    "ItemRow" => $itemRow
                 ]));
             }
-
-            $itemRows->push(new ArrayData([
-                "ItemRow" => $itemRow
-            ]));
             if ($item->hasMethod('destroy')) {
                 $item->destroy();
             }
diff --git a/src/Security/Group.php b/src/Security/Group.php
index eb279e111..aba30eaf6 100755
--- a/src/Security/Group.php
+++ b/src/Security/Group.php
@@ -635,6 +635,11 @@ class Group extends DataObject
             return true;
         }
 
+        // if user can grant access for specific groups, they need to be able to see the groups
+        if (Permission::checkMember($member, "SITETREE_GRANT_ACCESS")) {
+            return true;
+        }
+
         return false;
     }
 
diff --git a/tests/php/Control/DirectorTest.php b/tests/php/Control/DirectorTest.php
index 44c9e1980..febb59306 100644
--- a/tests/php/Control/DirectorTest.php
+++ b/tests/php/Control/DirectorTest.php
@@ -233,6 +233,9 @@ class DirectorTest extends SapphireTest
     public function testIsAbsoluteUrl()
     {
         $this->assertTrue(Director::is_absolute_url('http://test.com/testpage'));
+        $this->assertTrue(Director::is_absolute_url('https:/\\test.com'));
+        $this->assertTrue(Director::is_absolute_url('https:\\/test.com'));
+        $this->assertTrue(Director::is_absolute_url('https:\\\\test.com'));
         $this->assertTrue(Director::is_absolute_url('ftp://test.com'));
         $this->assertFalse(Director::is_absolute_url('test.com/testpage'));
         $this->assertFalse(Director::is_absolute_url('/relative'));
@@ -242,6 +245,11 @@ class DirectorTest extends SapphireTest
         $this->assertTrue(Director::is_absolute_url("https://test.com/?url=http://foo.com"));
         $this->assertTrue(Director::is_absolute_url("trickparseurl:http://test.com"));
         $this->assertTrue(Director::is_absolute_url('//test.com'));
+        $this->assertTrue(Director::is_absolute_url('\\/\\/test.com'));
+        $this->assertTrue(Director::is_absolute_url('\/\/test.com'));
+        $this->assertTrue(Director::is_absolute_url('/\\test.com'));
+        $this->assertTrue(Director::is_absolute_url('\\\\test.com'));
+        $this->assertFalse(Director::is_absolute_url('\\test.com'));
         $this->assertTrue(Director::is_absolute_url('/////test.com'));
         $this->assertTrue(Director::is_absolute_url('  ///test.com'));
         $this->assertTrue(Director::is_absolute_url('http:test.com'));
@@ -259,8 +267,17 @@ class DirectorTest extends SapphireTest
     {
         $this->assertFalse(Director::is_relative_url('http://test.com'));
         $this->assertFalse(Director::is_relative_url('https://test.com'));
+        $this->assertFalse(Director::is_relative_url('https:/\\test.com'));
+        $this->assertFalse(Director::is_relative_url('https:\\/test.com'));
+        $this->assertFalse(Director::is_relative_url('https:\\\\test.com'));
         $this->assertFalse(Director::is_relative_url('   https://test.com/testpage   '));
         $this->assertTrue(Director::is_relative_url('test.com/testpage'));
+        $this->assertFalse(Director::is_relative_url('//test.com'));
+        $this->assertFalse(Director::is_relative_url('\\/\\/test.com'));
+        $this->assertFalse(Director::is_relative_url('\/\/test.com'));
+        $this->assertFalse(Director::is_relative_url('/\\test.com'));
+        $this->assertFalse(Director::is_relative_url('\\\\test.com'));
+        $this->assertTrue(Director::is_relative_url('\\test.com'));
         $this->assertFalse(Director::is_relative_url('ftp://test.com'));
         $this->assertTrue(Director::is_relative_url('/relative'));
         $this->assertTrue(Director::is_relative_url('relative'));
@@ -402,17 +419,34 @@ class DirectorTest extends SapphireTest
         );
     }
 
-    /**
-     * Mostly tested by {@link testIsRelativeUrl()},
-     * just adding the host name matching aspect here.
-     */
     public function testIsSiteUrl()
     {
-        $this->assertFalse(Director::is_site_url("http://test.com"));
+        $this->assertFalse(Director::is_site_url('http://test.com'));
+        $this->assertTrue(Director::is_site_url('/relative-path'));
+        $this->assertTrue(Director::is_site_url('relative-path'));
         $this->assertTrue(Director::is_site_url(Director::absoluteBaseURL()));
-        $this->assertFalse(Director::is_site_url("http://test.com?url=" . Director::absoluteBaseURL()));
-        $this->assertFalse(Director::is_site_url("http://test.com?url=" . urlencode(Director::absoluteBaseURL() ?? '')));
-        $this->assertFalse(Director::is_site_url("//test.com?url=" . Director::absoluteBaseURL()));
+        $this->assertFalse(Director::is_site_url('http://test.com?url=' . Director::absoluteBaseURL()));
+        $this->assertFalse(Director::is_site_url('http://test.com?url=' . urlencode(Director::absoluteBaseURL() ?? '')));
+        $this->assertFalse(Director::is_site_url('http:\\\\test.com'));
+        $this->assertFalse(Director::is_site_url('http:\\\\test.com?url=' . Director::absoluteBaseURL()));
+        $this->assertFalse(Director::is_site_url('http:\\\\test.com?url=' . urlencode(Director::absoluteBaseURL() ?? '')));
+        $this->assertFalse(Director::is_site_url('http:\\/test.com'));
+        $this->assertFalse(Director::is_site_url('http:\\/test.com?url=' . Director::absoluteBaseURL()));
+        $this->assertFalse(Director::is_site_url('http:\\/test.com?url=' . urlencode(Director::absoluteBaseURL() ?? '')));
+        $this->assertFalse(Director::is_site_url('//test.com'));
+        $this->assertFalse(Director::is_site_url('//test.com?url=' . Director::absoluteBaseURL()));
+        $this->assertFalse(Director::is_site_url('\\/\\/test.com'));
+        $this->assertFalse(Director::is_site_url('\\/\\/test.com?url=' . Director::absoluteBaseURL()));
+        $this->assertFalse(Director::is_site_url('\/\/test.com'));
+        $this->assertFalse(Director::is_site_url('\/\/test.com?url=' . Director::absoluteBaseURL()));
+        $this->assertFalse(Director::is_site_url('\\/test.com'));
+        $this->assertFalse(Director::is_site_url('\\/test.com?url=' . Director::absoluteBaseURL()));
+        $this->assertFalse(Director::is_site_url('/\\test.com'));
+        $this->assertFalse(Director::is_site_url('/\\test.com?url=' . Director::absoluteBaseURL()));
+        $this->assertFalse(Director::is_site_url('\\\\test.com'));
+        $this->assertFalse(Director::is_site_url('\\\\test.com?url=' . Director::absoluteBaseURL()));
+        $this->assertTrue(Director::is_site_url('\\test.com'));
+        $this->assertTrue(Director::is_site_url('\\test.com?url=' . Director::absoluteBaseURL()));
         $this->assertFalse(Director::is_site_url('http://google.com\@test.com'));
         $this->assertFalse(Director::is_site_url('http://google.com/@test.com'));
         $this->assertFalse(Director::is_site_url('http://google.com:pass\@test.com'));
diff --git a/tests/php/Forms/GridField/GridFieldPrintButtonTest.php b/tests/php/Forms/GridField/GridFieldPrintButtonTest.php
index 59e73a494..f78c305ba 100644
--- a/tests/php/Forms/GridField/GridFieldPrintButtonTest.php
+++ b/tests/php/Forms/GridField/GridFieldPrintButtonTest.php
@@ -32,6 +32,19 @@ class GridFieldPrintButtonTest extends SapphireTest
     }
 
     public function testLimit()
+    {
+        $this->assertEquals(42, $this->getTestableRows()->count());
+    }
+
+    public function testCanViewIsRespected()
+    {
+        $orig = TestObject::$canView;
+        TestObject::$canView = false;
+        $this->assertEquals(0, $this->getTestableRows()->count());
+        TestObject::$canView = $orig;
+    }
+
+    private function getTestableRows()
     {
         $list = TestObject::get();
 
@@ -48,7 +61,6 @@ class GridFieldPrintButtonTest extends SapphireTest
 
         // Printed data should ignore pagination limit
         $printData = $button->generatePrintData($gridField);
-        $rows = $printData->ItemRows;
-        $this->assertEquals(42, $rows->count());
+        return $printData->ItemRows;
     }
 }
diff --git a/tests/php/Forms/GridField/GridFieldPrintButtonTest/TestObject.php b/tests/php/Forms/GridField/GridFieldPrintButtonTest/TestObject.php
index 2e8f80cc9..dd5638d09 100644
--- a/tests/php/Forms/GridField/GridFieldPrintButtonTest/TestObject.php
+++ b/tests/php/Forms/GridField/GridFieldPrintButtonTest/TestObject.php
@@ -12,4 +12,11 @@ class TestObject extends DataObject implements TestOnly
     private static $db = [
         'Name' => 'Varchar'
     ];
+
+    public static bool $canView = true;
+
+    public function canView($member = null)
+    {
+        return static::$canView;
+    }
 }