diff -up xfce4-settings-4.16.0/dialogs/mime-settings/xfce-mime-helper.c.BAK xfce4-settings-4.16.0/dialogs/mime-settings/xfce-mime-helper.c
--- xfce4-settings-4.16.0/dialogs/mime-settings/xfce-mime-helper.c.BAK	2022-11-10 14:46:34.496823705 +0800
+++ xfce4-settings-4.16.0/dialogs/mime-settings/xfce-mime-helper.c	2022-11-10 14:51:50.390633576 +0800
@@ -375,7 +375,7 @@ xfce_mime_helper_execute (XfceMimeHelper
   gint          status;
   gint          result;
   gint          pid;
-  const gchar  *real_parameter = parameter;
+  gchar        *real_parameter = NULL;
 
   // FIXME: startup-notification
 
@@ -387,23 +387,44 @@ xfce_mime_helper_execute (XfceMimeHelper
   if (G_UNLIKELY (screen == NULL))
     screen = gdk_screen_get_default ();
 
-  /* strip the mailto part if needed */
-  if (real_parameter != NULL && g_str_has_prefix (real_parameter, "mailto:"))
-    real_parameter = parameter + 7;
+  if (parameter != NULL)
+  {
+    if (helper->category == XFCE_MIME_HELPER_WEBBROWSER || helper->category == XFCE_MIME_HELPER_FILEMANAGER)
+      {
+        /* escape characters which do not belong into an URI/URL */
+        real_parameter = g_uri_escape_string (parameter, ":/?#[]@!$&'()*+,;=%", TRUE);
+      }
+    else if (g_str_has_prefix (real_parameter, "mailto:"))
+      {
+        /* strip the mailto part if needed */
+        real_parameter = g_strdup (parameter + 7);
+      }
+    else
+      {
+        real_parameter = g_strdup (parameter);
+      }
+  }
 
   /* determine the command set to use */
-  if (exo_str_is_flag (real_parameter)) {
+  if (exo_str_is_flag (real_parameter))
+  {
     commands = helper->commands_with_flag;
-  } else if (exo_str_is_empty (real_parameter)) {
+  }
+  else if (exo_str_is_empty (real_parameter))
+  {
     commands = helper->commands;
-  } else {
+  }
+  else
+  {
     commands = helper->commands_with_parameter;
   }
 
+
   /* verify that we have atleast one command */
   if (G_UNLIKELY (*commands == NULL))
     {
       g_set_error (error, G_SPAWN_ERROR, G_SPAWN_ERROR_INVAL, _("No command specified"));
+      g_free (real_parameter);
       return FALSE;
     }
 
@@ -493,6 +514,7 @@ xfce_mime_helper_execute (XfceMimeHelper
   if (G_UNLIKELY (!succeed))
     g_propagate_error (error, err);
 
+  g_free (real_parameter);
   return succeed;
 }