CVE-2021-47698Network attack vectorHinoki check available

Authenticated script execution via unescaped Views URL

Published Nov 3, 2025 · Updated Nov 3, 2025

Cross-site scripting in Nagios XI before 5.8.7 allows remote authenticated users to execute script through a crafted Core Views URL. The embedded Core UI renders attacker-controlled URL input without applying escape_string() to neutralize it before inclusion in the response. A valid low-privilege session and victim interaction with the crafted URL are required, limiting the result to script execution in the victim's browser context.

CVSS severity5.4
Medium
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Cross-site scripting in Nagios XI before 5.8.7 allows remote authenticated users to execute script through a crafted Core Views URL. The embedded Core UI renders attacker-controlled URL input without applying escape_string() to neutralize it before inclusion in the response. A valid low-privilege session and victim interaction with the crafted URL are required, limiting the result to script execution in the victim's browser context.

The record

CVE
CVE-2021-47698
Published
Nov 3, 2025
Updated
Nov 3, 2025
Vendor
Nagios Enterprises, LLC
Product
Nagios XI
Classifications
CWE-79, CAPEC-63, T1204.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 3, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 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 <5.8.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Nagios Enterprises, LLC · Nagios XIversion=0 <5.8.7

Published CVSS scores

5.4NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
5.1VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

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')
CAPEC-63Cross-Site Scripting (XSS)
T1204.001User Execution: Malicious Link

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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