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CVE-2026-31981 Nozomi Networks CVE debrief

CVE-2026-31981 is a Stored HTML Injection vulnerability in Nozomi Networks N2OS, allowing an authenticated user with administrative privileges to inject malicious HTML tags into configuration data. When viewed by a victim in the Diagram tab and Graph view, the injected HTML renders, enabling phishing and possibly open redirect attacks. The vulnerability exists due to insufficiently restrictive input validation in the Diagram tab and Graph view of N2OS. The existing input validation and Content Security Policy configuration prevent full XSS exploitation and direct information disclosure. Organizations using Nozomi Networks N2OS should prioritize patching CVE-2026-31981. Administrators with access to the Diagram tab and Graph view are at risk of exploitation.

Vendor
Nozomi Networks
Product
Guardian
CVSS
MEDIUM 4.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-09
Original CVE updated
2026-08-11
Advisory published
2026-07-09
Advisory updated
2026-08-11

Who should care

Organizations using Nozomi Networks N2OS should prioritize patching CVE-2026-31981. Administrators with access to the Diagram tab and Graph view are at risk of exploitation. Security teams should review the NVD entry and vendor advisory for mitigation guidance.

Technical summary

The vulnerability exists due to insufficiently restrictive input validation in the Diagram tab and Graph view of N2OS. An authenticated user with administrative privileges can inject malicious HTML tags into configuration data through multiple input vectors. The existing input validation and Content Security Policy configuration prevent full XSS exploitation and direct information disclosure. The affected product is Nozomi Networks N2OS, and the vulnerability has a CVSS score of 4.8 and a severity of MEDIUM.

Defensive priority

Medium priority due to the requirement for administrative privileges and the limited impact of the vulnerability.

Recommended defensive actions

  • Apply the patch mentioned in the vendor advisory
  • Review and update input validation for the Diagram tab and Graph view
  • Monitor for suspicious activity in N2OS configuration data
  • Enforce Content Security Policy
  • Restrict administrative access to the Diagram tab and Graph view
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record was published on 2026-07-09T08:16:47.483Z and last modified on 2026-07-10T13:15:29.023Z. The NVD entry is currently Analyzed. The vendor advisory provides mitigation guidance. Evidence is limited to public sources and may not reflect the full scope or impact of the vulnerability. Defenders should verify the affected product deployments and review the vendor advisory for specific mitigation guidance.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-31981 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-31981

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-31981 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-31981

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.