Mitel MiVoice Office 400 stored Cross-Site ScriptingCVE-2026-104808

DigitalCanion has discovered a stored Cross-Site Scripting (XSS) vulnerability that allows an authenticated malicious user to inject persistent JavaScript or HTML content, resulting in a denial-of-service condition within the web application. The specific flaw exists within the web portal listening on TCP port 443, under Configuration → Users → Users List. The vulnerability occurs in the “Microsoft Exchange mailbox” field, which fails to properly validate or sanitize user-supplied input before storing and rendering it. By injecting malicious JavaScript into this field, an attacker can cause the payload to execute whenever the affected user properties are accessed. This can prevent access to the affected user properties and result in a denial-of-service condition within the application's user-management functionality.

Quoted source text, attributed separately from HOL analysis.