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NVD / CVE Program· CNA Nozomi

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

MediumCVSS 4.8 · v4.0—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 19/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.25% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. Administrator privileges are required. No special conditions are required; it is repeatable.
  • Fixed version: Nozomi Networks CMC 26.2.0; Nozomi Networks Guardian 26.2.0.

Low priority for now. Upgrade to Nozomi Networks CMC 26.2.0; Nozomi Networks Guardian 26.2.0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

Published
Jul 9, 2026
Updated
Aug 11, 2026
EPSS
0.2% · 16th percentile

Report tools

JSON

Action score

19

Monitor

Low priority for now.

CVSS
19 / 40 · 4.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Nozomi
4.8
NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
nozominetworkscmc
nozominetworksguardian

Limit the impact of XSS

This is a cross-site scripting (XSS) vulnerability. A well-configured Content-Security-Policy doesn't fix it, but greatly reduces its impact. Check your site's CSP and other security headers for free.

Check security headers

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Nozomi). Independent of NVD's CPE analysis and usually ahead of it.

  • Nozomi Networks CMC

    • before 26.2.0affected · semver

  • Nozomi Networks Guardian

    • before 26.2.0affected · semver

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • nozominetworks cmcbefore 26.2.0
  • nozominetworks guardianbefore 26.2.0

Same product

nozominetworks: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-29245SQL Injection on IDS parsing of malformed asset fields in Guardian/CMC >= 22.6.0 before 22.6.3 and 23.1.0
    36Monitor
  • CVE-2026-31984DoS through oversized audit log entries in Guardian/CMC before 26.2.0
    34Monitor
  • CVE-2023-2567Authenticated SQL Injection on Query functionality in Guardian/CMC before 22.6.3 and 23.1.0
    34Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2025-40903May 19, 2026 · HTML injection in Schedule Restore Archive in Guardian/CMC before 26.1.0
    19Monitor
  • ← EarlierCVE-2025-40904May 19, 2026 · HTML injection in Smart Polling in Guardian/CMC before 26.1.0
    20Monitor
  • Later →CVE-2026-31982Jul 9, 2026 · Open Redirect in SAML Single Sign-On in Guardian/CMC before 26.2.0
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Nozomi Networks CMC26.2.0Vendor (CNA)
Nozomi Networks Guardian26.2.0Vendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2025-40892203 days apartStored Cross-Site Scripting (XSS) in Reports in Guardian/CMC before 25.5.0
    28Monitor
  • CVE-2025-40893203 days apartHTML injection in Asset List in Guardian/CMC before 25.5.0
    21Monitor
  • CVE-2025-4090451 days apartHTML injection in Smart Polling in Guardian/CMC before 26.1.0
    20Monitor
  • CVE-2025-4090151 days apartHTML injection in Credentials Manager in Guardian/CMC before 26.1.0
    19Monitor
  • CVE-2025-4090251 days apartHTML injection in Users in Guardian/CMC before 26.1.0
    19Monitor
  • CVE-2025-4090351 days apartHTML injection in Schedule Restore Archive in Guardian/CMC before 26.1.0
    19Monitor

Not on record for this CVE: EPSS history · patch commit or PR link · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • Administrator privileges are required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
High
User interaction
P
Scope
X

Weakness class (CWE)

CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Root cause

User content is inserted into the page as HTML. The browser interprets the content as code rather than data.

The bug in code

The whole CWE-79 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
commentEl.innerHTML = comment.body;

Fixed

ts
commentEl.textContent = comment.body;

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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