CVE-2026-104808: DigitalCanion has discovered a stored Cross-Site Scripting (XSS) vulnerability that allows an authenticated malicious user to inject persistent JavaScript or HT

DigitalCanion has discovered a stored Cross-Site Scripting (XSS) vulnerability that allows an authenticated malicious user to inject persistent JavaScript or HT

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.

Description from the National Vulnerability Database, published by vulnerability@ncsc.ch

What it means for a small business

Mitel MiVoice Office 400 handles email and office work, which is where invoices, logins and customer details live. Check that every computer and server running it has the update, including the one in the back office nobody touches.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.25%, higher than 15% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 28, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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