CVE-2026-48550

Medium

Description

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.

SeverityMedium

CVSS6.1

Exploit probability—

ProductNagios Core

PublishedAug 12, 2026

First seenAug 12, 2026

Weakness typeCWE-79Cross-site scripting (XSS)

How to fix

Update

Nagios Enterprises, LLC. Nagios Core4.5.14 or later
Nagios Enterprises, LLC. Nagios XI2026R1.7 or later

Patches

nagios.com/security-disclosures/nagios-core/

Vendor advisories

github.com/NagiosEnterprises/nagioscore/blob/master/Changelog

Affected products

Product	Affected versions	Fixed in
Nagios Enterprises, LLC. Nagios Core	v < 4.5.14	4.5.14
Nagios Enterprises, LLC. Nagios XI	v < 2026R1.7	2026R1.7

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