Twig is a template language for PHP. In a sandbox, an attacker can call `__toString()` on an object even if the `__toString()` method is not allowed by the security policy when the object is part of an array or an argument list (arguments to a function or a filter for instance). This issue has been patched in versions 3.11.2 and 3.14.1. All users are advised to upgrade. There are no known workarounds for this issue.