CVE-2026-48552Network attack vectorHinoki check available

Authenticated JavaScript execution via unsanitized JSON rendering

Published Aug 12, 2026 · Updated Aug 12, 2026

DOM-based XSS in jsonquery.js in Nagios Core before 4.5.14 and Nagios XI before 2026R1.7 allows remote authenticated users to execute JavaScript. The script inserts unencoded JSON string values reflected from stored fields into the DOM instead of applying contextual output encoding. Low-privileged remote access is required to store a payload, and execution occurs when another user opens the affected JSON query interface.

CVSS severity5.1
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

DOM-based XSS in jsonquery.js in Nagios Core before 4.5.14 and Nagios XI before 2026R1.7 allows remote authenticated users to execute JavaScript. The script inserts unencoded JSON string values reflected from stored fields into the DOM instead of applying contextual output encoding. Low-privileged remote access is required to store a payload, and execution occurs when another user opens the affected JSON query interface.

The record

CVE
CVE-2026-48552
Published
Aug 12, 2026
Updated
Aug 12, 2026
Vendor
Nagios Enterprises, LLC
Product
Nagios Core
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 12, 2026Record 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 <4.5.14

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Nagios Enterprises, LLC · Nagios Coreversion=0 <4.5.14
Nagios Enterprises, LLC · Nagios XIversion=0 <2026R1.7

Published CVSS scores

5.4Amazon LinuxCVSS: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')
T1059.007Command and Scripting Interpreter: JavaScript

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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