An HTML injection vulnerability in Amidaware Inc Tactical RMM v1.3.1 and earlier allows authenticated users to inject arbitrary HTML content during the creation of a new agent via the POST /api/v3/newagent/ endpoint. The agent_id parameter accepts up to 255 characters and is improperly sanitized using DOMPurify.sanitize() with the html: true option enabled, which fails to adequately filter HTML input. The injected HTML is rendered in the Tactical RMM management panel when an administrator attempts to remove or shut down the affected agent, potentially leading to client-side attacks such as UI manipulation or phishing. NOTE: the Supplier's position is that this has incorrect information.