What’s Vulnerable › Vulnerabilities

CVE-2026-31981: HTML injection in Diagram tab and Graph view in Guardian/CMC before 26.2.0

• Severity: medium (CVSS 4.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-09 · updated 2026-08-11
• Weakness: CWE-79

Description

A Stored HTML Injection vulnerability was discovered in the Diagram tab and Graph view due to a shared input validation function being insufficiently restrictive. An authenticated user with administrative privileges can inject malicious HTML tags into N2OS configuration data through multiple input vectors. When a victim views the affected data in the Diagram tab and Graph view, 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 products

• Nozomi Networks CMC: before 26.2.0 — fixed in 26.2.0
• Nozomi Networks Guardian: before 26.2.0 — fixed in 26.2.0

How to fix

Upgrade to a fixed version: Nozomi Networks CMC 26.2.0; Nozomi Networks Guardian 26.2.0. Check the vendor advisory for mitigations.

References

• https://security.nozominetworks.com/NN-2026:8-01
• https://cert-portal.siemens.com/productcert/html/ssa-827968.html

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