CVE-2025-40903 HTML injection in Schedule Restore Archive in Guardian/CMC before 26.1.0

Medium 4.8 Published Updated

An authenticated admin can inject HTML into restore schedules, enabling phishing or open redirects when viewed by victims.

Exploited in the wild
Not known
Login needed
An administrator
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
None listed

What is CVE-2025-40903?

CVE-2025-40903 is a medium-severity cross-site scripting vulnerability in Nozomi Networks CMC, published on 19 May 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

Official description

A Stored HTML Injection vulnerability was discovered in the Schedule Restore Archive functionality due to improper validation of an input parameter. An authenticated user with administrative privileges can define a malicious restore schedule containing HTML tags. When a victim views the affected schedule, the injected HTML renders in their browser, enabling phishing and possibly open redirect attacks. Full XSS exploitation and direct information disclosure are prevented by the existing input validation and Content Security Policy configuration.

Weakness: CWE-79

Which versions are affected by CVE-2025-40903?

It affects 2 products.

Products include Nozominetworks Cmc, Nozominetworks Guardian.

How do I fix CVE-2025-40903?

No fix has been published for CVE-2025-40903 yet. Limit exposure of the affected software until one is available.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2025-40903 being exploited?

There is no known exploitation of CVE-2025-40903 in the wild and no public exploit code.

Sources

Also known as GHSA-9pfj-vxgx-63wq.

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