The GOV.UK Theme (govuk_theme) is a Drupal theme for the GOV.UK Design System.
The theme doesn't sanitize user input in certain cases, which leads to Cross-Site-Scripting (XSS) vulnerabilities. An attacker that can create or edit certain entities or configuration may be able to exploit one or more Cross-Site-Scripting (XSS) vulnerabilities to target visitors of the site, including site admins with privileged access.
The vulnerability is mitigated by the facts, that: