CVE-2026-31981 PUBLISHED

HTML injection in Diagram tab and Graph view in Guardian/CMC before 26.2.0

Assigner: Nozomi
Reserved: 10.03.2026 Published: 09.07.2026 Updated: 09.07.2026

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.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L
CVSS Score: 4.8

Product Status

Vendor Nozomi Networks
Product Guardian
Versions Default: unaffected
  • affected from 0 to 26.2.0 (excl.)
Vendor Nozomi Networks
Product CMC
Versions Default: unaffected
  • affected from 0 to 26.2.0 (excl.)

Workarounds

Review all accounts with administrative access to it and delete unnecessary ones.

Solutions

Upgrade to v26.2.0 or later.

Credits

  • This issue was found by Stefano Libero and Andrea Palanca of Nozomi Networks Product Security team during an internal investigation. finder

References

Problem Types

  • CWE-79 Improper neutralization of input during web page generation ('cross-site scripting') CWE

Impacts

  • CAPEC-592 Stored XSS