# 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.

- **Severity:** Critical 9.4 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 30 Oct 2025
- **Updated:** 17 Nov 2025
- **Also known as:** GHSA-9f8q-34c7-3prr

## 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 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2020-36856?

It affects 1 product.


Products: 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.

## 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

- [CVE-2021-25296](https://insights.sbomify.com/CVE-2021-25296/): Nagios XI OS Command Injection (high 8.8, exploited in the wild)
- [CVE-2021-25297](https://insights.sbomify.com/CVE-2021-25297/): Nagios XI OS Command Injection (high 8.8, exploited in the wild)
- [CVE-2021-25298](https://insights.sbomify.com/CVE-2021-25298/): Nagios XI OS Command Injection (high 8.8, exploited in the wild)
- [CVE-2019-15949](https://insights.sbomify.com/CVE-2019-15949/): Nagios XI Remote Code Execution (high 8.8, exploited in the wild)
- [CVE-2024-24401](https://insights.sbomify.com/CVE-2024-24401/): SQL injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-36856 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2020-36856 in the wild and no public exploit code.

Affected product: Nagios Nagios Xi. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2020-36856/ (Markdown: https://insights.sbomify.com/CVE-2020-36856/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-36856
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-36856
- OSV: https://osv.dev/vulnerability/CVE-2020-36856

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-36856/
Summaries are generated and may contain mistakes; the official description above is the record.