---
id: CVE-2026-48553
title: >-
  Nagios Core before 4.5.13 and Nagios XI before 2026R1.5 are vulnerable to
  authenticated remote code execution via custom-variable macro injection
  through the Nagios Remote Data Processor (NRDP)
summary: >-
  Nagios Core before 4.5.13 and Nagios XI before 2026R1.5 are vulnerable to
  authenticated remote code execution via custom-variable macro injection
  through the Nagios Remote Data Processor (NRDP). When a custom variable
  defined on a host, …
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-78
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-2026-48553'
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-authenticated-rce-via-custom-variable-macro-injection
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00966
epssPercentile: 0.60138
ingestedAt: '2026-09-08T21:11:12.276Z'
---

## Overview

Nagios Core before 4.5.13 and Nagios XI before 2026R1.5 are vulnerable to authenticated remote code execution via custom-variable macro injection through the Nagios Remote Data Processor (NRDP). When a custom variable defined on a host, service, or contact is referenced in a shell-executed command line, an authenticated attacker with NRDP access can inject OS commands through the macro value. Exploitation requires a non-default configuration in which a custom variable is defined and referenced in a shell-executed command.

## Remediation

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