CVE-2026-48550: Nagios Enterprises, Llc Nagios Core

Medium severity, CVSS 6.1. EPSS: 0.4% chance of exploitation in the next 30 days.

Nagios Core before 4.5.14 and Nagios XI before 2026R1.7 are vulnerable to reflected cross-site scripting in cmd.cgi via the NagFormId parameter. An unauthenticated remote attacker can craft a malicious link that, when followed by an authenticated user, executes 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.