diff --git a/apps/qubit/modules/informationobject/actions/browseAction.class.php b/apps/qubit/modules/informationobject/actions/browseAction.class.php
index a64621ee8e..1bd4c79d2f 100644
--- a/apps/qubit/modules/informationobject/actions/browseAction.class.php
+++ b/apps/qubit/modules/informationobject/actions/browseAction.class.php
@@ -133,6 +133,20 @@ public function execute($request)
             $this->collection = QubitInformationObject::getById($this->getParameters['collection']);
         }
 
+        if (isset($this->getParameters['mediatypes'])) {
+            $validMediaTypes = [
+                'audio' => QubitTerm::AUDIO_ID,
+                'image' => QubitTerm::IMAGE_ID,
+                'text' => QubitTerm::TEXT_ID,
+                'video' => QubitTerm::VIDEO_ID,
+                'other' => QubitTerm::OTHER_ID,
+            ];
+
+            if (false == array_search($this->getParameters['mediatypes'], $validMediaTypes)) {
+                $this->getParameters['mediatypes'] = QubitTerm::OTHER_ID;
+            }
+        }
+
         // Set search realm if searching by repository
         if (isset($request->repos) && ctype_digit($request->repos)) {
             // Add repo to the user session as realm
diff --git a/vendor/symfony/lib/request/sfWebRequest.class.php b/vendor/symfony/lib/request/sfWebRequest.class.php
index 2278446258..5fb0435ce7 100644
--- a/vendor/symfony/lib/request/sfWebRequest.class.php
+++ b/vendor/symfony/lib/request/sfWebRequest.class.php
@@ -740,6 +740,11 @@ public function setFormat($format, $mimeTypes)
    */
   public function setRequestFormat($format)
   {
+    $validFormats = array_keys($this->formats);
+
+    if (false === array_search($format, $validFormats)) {
+        $format = 'html';
+    }
     $this->format = $format;
   }