Vulnerability · Published Aug 12, 2026 · Assigned by VulnCheck

CVE-2026-48552Nagios Core / XI DOM-based XSS via jsonquery.js

Medium 5.4

In plain English

A medium-severity cross-site scripting in Nagios Core from Nagios Enterprises, LLC.. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.4Medium
Exploit odds (30 days)0.3%top 78.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Nagios Core before 4.5.14 and Nagios XI before 2026R1.7 are vulnerable to DOM-based cross-site scripting in jsonquery.js. Unencoded JSON string values reflected from stored fields are inserted into the DOM without sanitization, allowing attackers to run arbitrary JavaScript in the victim's browser.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12nagios44.4.6-4+deb12u2DEBIAN-CVE-2026-48552
Debian:13nagios44.4.6-4.1+deb13u2DEBIAN-CVE-2026-48552
Debian:14nagios44.5.14+ds-1DEBIAN-CVE-2026-48552
Ubuntu:22.04:LTSnagios4no fix listedUBUNTU-CVE-2026-48552
Ubuntu:24.04:LTSnagios4no fix listedUBUNTU-CVE-2026-48552
Ubuntu:26.04:LTSnagios4no fix listedUBUNTU-CVE-2026-48552
Ubuntu:26.10nagios4no fix listedUBUNTU-CVE-2026-48552

Affected products (as reported)

VendorProductVersions
Nagios Enterprises, LLC. Nagios Core 0 – before 4.5.14
Nagios Enterprises, LLC. Nagios XI 0 – before 2026R1.7

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

References