CVE-2020-36856 Nagios XI < 5.6.14 Authenticated RCE command_test.php via address
Authenticated attackers can execute arbitrary commands on Nagios XI hosts via shell metacharacter injection in the Core Config Manager.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2020-36856?
CVE-2020-36856 is a critical command injection vulnerability in Nagios Nagios Xi, published on 30 Oct 2025. An attacker needs administrator access to exploit it, with no action from the victim.
Official 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.
Weakness: CWE-78
Which versions are affected by CVE-2020-36856?
It affects 1 product.
Products include Nagios Nagios Xi.
How do I fix CVE-2020-36856?
No fix has been published for CVE-2020-36856 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2020-36856 being exploited?
There is no known exploitation of CVE-2020-36856 in the wild and no public exploit code.
Other vulnerabilities in Nagios Nagios Xi
Sources
Also known as GHSA-9f8q-34c7-3prr.