CVE-2026-48552: Nagios Enterprises, Llc Nagios Core

Medium severity, CVSS 5.4. EPSS: 0.3% chance of exploitation in the next 30 days.

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 products

• Nagios Enterprises, Llc Nagios Core: before 4.5.14 (fixed in 4.5.14)
• Nagios Enterprises, Llc Nagios XI: before 2026R1.7 (fixed in 2026R1.7)

Published 2026-08-12. Last modified 2026-09-08.