UploadController now only accepts file extensions listed in config.yaml

src/Configuration/Config.php

@@ -173,4 +173,9 @@ class Config
     {
         return $this->get('contenttypes/' . $name);
     }
+
+    public function getFileTypes(): Collection
+    {
+        return new Collection($this->get('general/accept_file_types'));
+    }
 }

src/Controller/Backend/Async/UploadController.php

@@ -72,7 +72,7 @@ class UploadController implements AsyncZone
         $uploadHandler->addRule(
             'extension',
             [
-                'allowed' => ['jpg', 'jpeg', 'png', 'gif', 'webp', 'svg', 'pdf'],
+                'allowed' => array_merge($this->config->getMediaTypes()->toArray(), $this->config->getFileTypes()->toArray()),
             ],
             '{label} should be a valid file (jpg, jpeg, png, webp, svg or pdf)',
             'Upload file'