---
id: CVE-2026-48550
title: >-
  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
summary: >-
  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 auth…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
published: '2026-08-12'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T20:28:37.587'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-48550'
references:
  - url: 'https://github.com/NagiosEnterprises/nagioscore/blob/master/Changelog'
    label: disclosure@vulncheck.com
  - url: 'https://www.nagios.com/security-disclosures/nagios-core/'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/nagios-core-xi-cmd-cgi-reflected-xss-via-nagformid-parameter
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00438
epssPercentile: 0.35397
ingestedAt: '2026-09-08T21:11:12.276Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.