---
id: CVE-2026-48549
title: >-
  Nagios Core before 4.5.13 and Nagios XI before 2026R1.5 contains a CSRF
  vulnerability in cmd.cgi
summary: >-
  Nagios Core before 4.5.13 and Nagios XI before 2026R1.5 contains a CSRF
  vulnerability in cmd.cgi. When no Cookie header is present, the double-submit
  cookie protection can be bypassed by supplying matching NagFormId and
  nagFormId values …
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N'
cwe:
  - CWE-352
published: '2026-08-26'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T20:44:42.207'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-48549'
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-csrf-via-cmd-cgi-double-submit-cookie
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00256
epssPercentile: 0.15386
ingestedAt: '2026-09-24T20:51:40.230Z'
---

## Overview

Nagios Core before 4.5.13 and Nagios XI before 2026R1.5 contains a CSRF vulnerability in cmd.cgi. When no Cookie header is present, the double-submit cookie protection can be bypassed by supplying matching NagFormId and nagFormId values in the POST body, allowing a cross-site request to execute Nagios commands as a currently authenticated user.

## Remediation

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