CVE-2020-36856 CRITICAL

CVE-2020-36856: Nagios XI < 5.6.14 Authenticated RCE command_test.php via address

Vendor Nagios
Product XI
Weakness CWE-78
Published October 30, 2025
Last update November 17, 2025

CVSS base score

9.4/10
Attack vector Network
Attack complexity Low
Privileges required High
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

What the vulnerability does

01Description

Nagios XI versions prior to 5.6.14 contain an authenticated remote command execution vulnerability in the CCM command_test.php script. Insufficient validation of the `address` parameter allows an authenticated user with access to the Core Config Manager to inject shell metacharacters that are incorporated into backend command invocations. Successful exploitation enables arbitrary command execution with the privileges of the Nagios XI web application user and may be leveraged to execute commands on the underlying XI host, modify system configuration, or fully compromise the host.

Key dates

02Disclosure timeline

October 30, 2025 CVE published
November 17, 2025 Record updated