CVE-2025-40890Network attack vector

Stored XSS via improperly validated dashboard input

Published Nov 25, 2025 · Updated Nov 26, 2025

Stored XSS in Nozomi Networks Guardian and CMC before 25.4.0 allows remote authenticated users to execute scripts in victims' browsers. The Dashboards functionality stores a JavaScript payload from an improperly validated dashboard parameter and renders it when a shared dashboard is viewed or a template is imported. Low-privilege access and victim interaction are required; execution can modify application data, interrupt service, or read limited sensitive information.

CVSS severity5.9
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Nozomi Networks Guardian and CMC before 25.4.0 allows remote authenticated users to execute scripts in victims' browsers. The Dashboards functionality stores a JavaScript payload from an improperly validated dashboard parameter and renders it when a shared dashboard is viewed or a template is imported. Low-privilege access and victim interaction are required; execution can modify application data, interrupt service, or read limited sensitive information.

The record

CVE
CVE-2025-40890
Published
Nov 25, 2025
Updated
Nov 26, 2025
Vendor
Nozomi Networks
Product
Guardian
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 25, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 26, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <25.4.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Nozomi Networks · Guardianversion=0 <25.4.0
Nozomi Networks · Central Management Console (CMC)version=0 <25.4.0

Published CVSS scores

7.9Nozomi NetworksCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:H/A:H
5.9Nozomi NetworksCVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:A/VC:L/VI:H/VA:H/SC:L/SI:L/SA:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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