---
id: CVE-2025-40902
title: >-
  A Stored HTML Injection vulnerability was discovered in the Users
  functionality due to improper validation of an input parameter
summary: >-
  A Stored HTML Injection vulnerability was discovered in the Users
  functionality due to improper validation of an input parameter. An
  authenticated user with administrative privileges can create a malicious user
  whose username contains HT…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L'
cwe:
  - CWE-79
vendor: nozominetworks
product: cmc
affected:
  - cmc < 26.1.0
  - guardian < 26.1.0
patched:
  - cmc 26.1.0
  - guardian 26.1.0
published: '2026-05-19'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T13:10:00.187'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-40902'
references:
  - url: 'https://security.nozominetworks.com/NN-2026:5-01'
    label: prodsec@nozominetworks.com
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-827968.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
epss: 0.00194
epssPercentile: 0.08476
ingestedAt: '2026-10-14T13:30:58.502Z'
---

## Overview

A Stored HTML Injection vulnerability was discovered in the Users functionality due to improper validation of an input parameter. An authenticated user with administrative privileges can create a malicious user whose username contains HTML tags. When a victim attempts to delete a group containing the affected user, 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.

## Affected

- `cmc < 26.1.0`
- `guardian < 26.1.0`

## Remediation

Upgrade past the affected range:

- `cmc 26.1.0`
- `guardian 26.1.0`