What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-10-30 · updated 2026-10-18
• Weakness: CWE-78

Description

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.

Affected products

• Nagios XI: before 5.6.14 — fixed in 5.6.14

How to fix

Upgrade to a fixed version: Nagios XI 5.6.14. Check the vendor advisory for mitigations.

References

• https://www.nagios.com/changelog/nagios-xi/
• https://www.nagios.com/products/security/#nagios-xi
• https://www.vulncheck.com/advisories/nagios-xi-authenticated-rce-command-test-php-via-address

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