Updated Yaml rendering

Author: rimi-itk

modules/os2forms_fordelingskomponent_debug/src/Controller/AbstractController.php

@@ -21,9 +21,11 @@ protected function formatDatetime(?int $timestamp): ?string {
   /**
    * Render YAML.
    */
-  protected function renderYaml(?\JsonSerializable $value): string {
-    return '<pre><code>' . Yaml::dump(json_decode(json_encode($value), TRUE),
-        inline: PHP_INT_MAX) . '</code></pre>';
+  protected function renderYaml(?\JsonSerializable $value): string
+  {
+    return '<pre><code>'
+      . htmlspecialchars(Yaml::dump(json_decode(json_encode($value), TRUE), inline: PHP_INT_MAX))
+      . '</code></pre>';
   }
 
 }