diff --git a/concrete/blocks/file/view.php b/concrete/blocks/file/view.php
index ba943b0a8e0..908f465258f 100644
--- a/concrete/blocks/file/view.php
+++ b/concrete/blocks/file/view.php
@@ -16,7 +16,7 @@
     ?>
     <div class="ccm-block-file">
         <a href="<?php echo (!empty($forceDownload)) ? $f->getForceDownloadURL() : $f->getDownloadURL(); ?>">
-            <?php echo stripslashes($controller->getLinkText()) ?>
+            <?php echo h(stripslashes($controller->getLinkText())) ?>
         </a>
     </div>
     <?php
diff --git a/concrete/controllers/dialog/express/preset/delete.php b/concrete/controllers/dialog/express/preset/delete.php
index d067bc102bd..3a2a528bf3e 100644
--- a/concrete/controllers/dialog/express/preset/delete.php
+++ b/concrete/controllers/dialog/express/preset/delete.php
@@ -71,7 +71,7 @@ public function remove_search_preset()
                     }
                     if (!$this->error->has()) {
                         $response = new EditResponse();
-                        $response->setMessage(t('%s deleted successfully.', $searchPreset->getPresetName()));
+                        $response->setMessage(t('%s deleted successfully.', h($searchPreset->getPresetName())));
                         $response->setAdditionalDataAttribute('presetID', $presetID);
                         $em = $this->app->make(\Doctrine\ORM\EntityManager::class);
                         $em->remove($searchPreset);
diff --git a/concrete/controllers/dialog/file/preset/delete.php b/concrete/controllers/dialog/file/preset/delete.php
index 6c30407cf8e..f2e73174491 100644
--- a/concrete/controllers/dialog/file/preset/delete.php
+++ b/concrete/controllers/dialog/file/preset/delete.php
@@ -46,7 +46,7 @@ public function remove_search_preset()
                     }
                     if (!$this->error->has()) {
                         $response = new EditResponse();
-                        $response->setMessage(t('%s deleted successfully.', $searchPreset->getPresetName()));
+                        $response->setMessage(t('%s deleted successfully.', h($searchPreset->getPresetName())));
                         $response->setAdditionalDataAttribute('presetID', $presetID);
                         $node = TreeNodeSearchPreset::getNodeBySavedSearchID($presetID);
                         if (is_object($node)) {
diff --git a/concrete/controllers/dialog/search/preset/delete.php b/concrete/controllers/dialog/search/preset/delete.php
index 2a7a091b0e5..0a49f958305 100644
--- a/concrete/controllers/dialog/search/preset/delete.php
+++ b/concrete/controllers/dialog/search/preset/delete.php
@@ -48,7 +48,7 @@ public function remove_search_preset()
                     }
                     if (!$this->error->has()) {
                         $response = new EditResponse();
-                        $response->setMessage(t('%s deleted successfully.', $searchPreset->getPresetName()));
+                        $response->setMessage(t('%s deleted successfully.', h($searchPreset->getPresetName())));
                         $response->setAdditionalDataAttribute('presetID', $presetID);
                         $em = $this->app->make(EntityManager::class);
                         $em->remove($searchPreset);
diff --git a/concrete/controllers/dialog/search/preset/edit.php b/concrete/controllers/dialog/search/preset/edit.php
index 2df2da926fb..216c6ff0f3e 100644
--- a/concrete/controllers/dialog/search/preset/edit.php
+++ b/concrete/controllers/dialog/search/preset/edit.php
@@ -49,7 +49,7 @@ public function edit_search_preset()
                     }
                     if (!$this->error->has()) {
                         $response = new EditResponse();
-                        $response->setMessage(t('%s edited successfully.', $newPresetName));
+                        $response->setMessage(t('%s edited successfully.', h($newPresetName)));
                         $response->setAdditionalDataAttribute('presetID', $presetID);
                         $response->setAdditionalDataAttribute('actionURL', (string) $this->getSavedSearchBaseURL($searchPreset));
                         $searchPreset->setPresetName($newPresetName);
diff --git a/concrete/single_pages/dashboard/system/calendar/colors.php b/concrete/single_pages/dashboard/system/calendar/colors.php
index 52ff99e7999..aa9b3492e6a 100644
--- a/concrete/single_pages/dashboard/system/calendar/colors.php
+++ b/concrete/single_pages/dashboard/system/calendar/colors.php
@@ -8,11 +8,11 @@
         <legend><?=t('Default Colors')?></legend>
         <div class="form-group">
             <?=$form->label('defaultBackgroundColor', t('Background'))?>
-            <?=$color->output('defaultBackgroundColor', $defaultBackgroundColor)?>
+            <?=$color->output('defaultBackgroundColor', h($defaultBackgroundColor))?>
         </div>
         <div class="form-group">
             <?=$form->label('defaultTextColor', t('Text'))?>
-            <?=$color->output('defaultTextColor', $defaultTextColor)?>
+            <?=$color->output('defaultTextColor', h($defaultTextColor))?>
         </div>
     </fieldset>
 
@@ -45,10 +45,10 @@
                 <tr>
                     <td style="text-align: center; width: 10px"><?=$form->checkbox('override[]', $topic->getTreeNodeID(), $checked)?></td>
                     <td style="width: 50%"><?=$topic->getTreeNodeDisplayName()?></td>
-                    <td><?=$color->output('backgroundColor[' . $topic->getTreeNodeID() . ']', $backgroundColor)?></td>
-                    <td><?=$color->output('textColor[' . $topic->getTreeNodeID() . ']', $textColor)?></td>
+                    <td><?=$color->output('backgroundColor[' . $topic->getTreeNodeID() . ']', h($backgroundColor))?></td>
+                    <td><?=$color->output('textColor[' . $topic->getTreeNodeID() . ']', h($textColor))?></td>
                 </tr>
-            <?php 
+            <?php
 }
     ?>
             </table>
diff --git a/concrete/src/StyleCustomizer/Inline/StyleSet.php b/concrete/src/StyleCustomizer/Inline/StyleSet.php
index 1d9b13551c7..f5156ba5942 100644
--- a/concrete/src/StyleCustomizer/Inline/StyleSet.php
+++ b/concrete/src/StyleCustomizer/Inline/StyleSet.php
@@ -256,8 +256,14 @@ public static function populateFromRequest(Request $request)
 
         $v = $post->get('customClass');
         if (is_array($v)) {
-            $set->setCustomClass(implode(' ', $v));
-            $return = true;
+            $v = array_filter($v, function ($class) {
+                return preg_match('/^-?[_a-zA-Z]+[_a-zA-Z0-9-]*$/', $class);
+            });
+
+            if (count($v) > 0) {
+                $set->setCustomClass(implode(' ', $v));
+                $return = true;
+            }
         }
 
         $v = trim($post->get('customID', ''));
diff --git a/concrete/views/dialogs/search/preset/delete.php b/concrete/views/dialogs/search/preset/delete.php
index e7b35bda8ae..ff25a3ca9e6 100644
--- a/concrete/views/dialogs/search/preset/delete.php
+++ b/concrete/views/dialogs/search/preset/delete.php
@@ -4,7 +4,7 @@
     <form method="post" data-dialog-form="remove-search-preset" class="form-horizontal" action="<?= $controller->getDeleteSearchPresetAction(); ?>">
         <?= $token->output('remove_search_preset'); ?>
         <?= $form->hidden('presetID', $searchPreset->getId()); ?>
-        <p><?= t('Are you sure you want to remove the "%s" search preset?', $searchPreset->getPresetName()); ?></p>
+        <p><?= t('Are you sure you want to remove the "%s" search preset?', h($searchPreset->getPresetName())); ?></p>
 
         <div class="dialog-buttons clearfix">
             <button class="btn btn-secondary" data-dialog-action="cancel"><?= t('Cancel'); ?></button>
diff --git a/concrete/views/dialogs/search/preset/edit.php b/concrete/views/dialogs/search/preset/edit.php
index 2a60468c318..fdfb31be888 100644
--- a/concrete/views/dialogs/search/preset/edit.php
+++ b/concrete/views/dialogs/search/preset/edit.php
@@ -6,7 +6,7 @@
         <?= $form->hidden('presetID', $searchPreset->getId()); ?>
         <div class="form-group">
             <?= $form->label('presetName', t('Name')); ?>
-            <?= $form->text('presetName', $searchPreset->getPresetName()); ?>
+            <?= $form->text('presetName', h($searchPreset->getPresetName())); ?>
         </div>
 
         <div class="dialog-buttons clearfix">