Dolibarr is an enterprise resource planning (ERP) and customer relationship management (CRM) software package. Version 18.0.4 has a HTML Injection vulnerability in the Home page of the Dolibarr Application. This vulnerability allows an attacker to inject arbitrary HTML tags and manipulate the rendered content in the application's response. Specifically, I was able to successfully inject a new HTML tag into the returned document and, as a result, was able to comment out some part of the Dolibarr App Home page HTML code. This behavior can be exploited to perform various attacks like Cross-Site Scripting (XSS). To remediate the issue, validate and sanitize all user-supplied input, especially within HTML attributes, to prevent HTML injection attacks; and implement proper output encoding when rendering user-provided data to ensure it is treated as plain text rather than executable HTML.