Halo is an open source website building tool. A security vulnerability has been identified in versions prior to 2.17.0 of the Halo project. This vulnerability allows an attacker to execute malicious scripts in the user's browser through specific HTML and JavaScript code, potentially leading to a Cross-Site Scripting (XSS) attack. Users are advised to upgrade to version 2.17.0+. There are no known workarounds for this vulnerability.