HTML injection in Diagram tab and Graph view in Guardian/CMC before 26.2.0
Summary
| CVE | CVE-2026-31981 |
|---|---|
| State | PUBLISHED |
| Assigner | Nozomi |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-09 08:16:47 UTC |
| Updated | 2026-07-09 16:39:17 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 4.8 MEDIUM from [email protected]
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
Problem Types: CWE-79 | CWE-79 CWE-79 Improper neutralization of input during web page generation ('cross-site scripting')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 4.8 | MEDIUM | 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/C... |
| 4.0 | CNA | CVSS | 4.8 | MEDIUM | 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 |
| 3.1 | [email protected] | Secondary | 5.9 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L |
| 3.1 | CNA | CVSS | 5.9 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L |
CVSS v4.0 Breakdown
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
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Nozomi Networks | Guardian | affected 26.2.0 semver | Not specified |
| CNA | Nozomi Networks | CMC | affected 26.2.0 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| security.nozominetworks.com/NN-2026:8-01 | [email protected] | security.nozominetworks.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: This issue was found by Stefano Libero and Andrea Palanca of Nozomi Networks Product Security team during an internal investigation. (en)
Additional Advisory Data
Solutions
CNA: Upgrade to v26.2.0 or later.
Workarounds
CNA: Use internal firewall features to limit access to the web management interface.
CNA: Review all accounts with administrative access to it and delete unnecessary ones.