---
id: CVE-2026-48548
title: >-
  Nagios Core before 4.5.12 contains a cross-site request forgery vulnerability
  in cmd.cgi where the CSRF protection mechanism passes validation when the
  NagFormId cookie is absent
summary: >-
  Nagios Core before 4.5.12 contains a cross-site request forgery vulnerability
  in cmd.cgi where the CSRF protection mechanism passes validation when the
  NagFormId cookie is absent. Attackers can craft a malicious cross-site POST
  request t…
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: '2026-09-24T20:43:32.537'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-48548'
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-csrf-via-cmd-cgi'
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00212
epssPercentile: 0.10191
ingestedAt: '2026-09-24T20:51:40.230Z'
---

## Overview

Nagios Core before 4.5.12 contains a cross-site request forgery vulnerability in cmd.cgi where the CSRF protection mechanism passes validation when the NagFormId cookie is absent. Attackers can craft a malicious cross-site POST request to execute arbitrary Nagios commands as a currently authenticated user without their knowledge or consent.

## Remediation

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