# CVE-2020-36858: Nagios Log Server < 2.1.6 XSS via Create User, Edit User, & Manage Host Lists Pages

> Attackers can inject arbitrary scripts into Nagios Log Server user and host management pages, potentially hijacking victim sessions.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 30 Oct 2025
- **Updated:** 17 Nov 2025
- **Also known as:** GHSA-wr48-wpx9-wpm2

## What is CVE-2020-36858?

CVE-2020-36858 is a medium-severity cross-site scripting vulnerability in Nagios Log Server, published on 30 Oct 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Nagios Log Server versions prior to 2.1.6 contain cross-site scripting (XSS) vulnerabilities via the web interface on the Create User, Edit User, and Manage Host Lists pages. Insufficient validation or escaping of user-supplied input may allow an attacker to inject and execute arbitrary script in the context of a victim's browser.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2020-36858?

It affects 1 product.


Products: Nagios Log Server.

## How do I fix CVE-2020-36858?

No fix has been published for CVE-2020-36858 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-36858 being exploited?

There is no known exploitation of CVE-2020-36858 in the wild and no public exploit code.

## Other vulnerabilities in Nagios Log Server

- [CVE-2025-44823](https://insights.sbomify.com/CVE-2025-44823/): Information disclosure in Log Server (critical 9.9)
- [CVE-2025-34277](https://insights.sbomify.com/CVE-2025-34277/): Nagios Log Server < 2024R1.3.1 RCE via Malformed Dashboard ID (critical 9.4)
- [CVE-2025-34274](https://insights.sbomify.com/CVE-2025-34274/): Nagios Log Server < 2024R2.0.3 Logstash Process Root Privileges (critical 9.3)
- [CVE-2023-7322](https://insights.sbomify.com/CVE-2023-7322/): Nagios Log Server < 2024R1 Incorrect Authorization Granting Full API Access (high 8.7)
- [CVE-2025-34271](https://insights.sbomify.com/CVE-2025-34271/): Nagios Log Server < 2024R2.0.2 Cluster Manager Credential Requests Sent Over Plaintext (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-36858 and fix it if it is affected.

What it is: CVE-2020-36858 is a medium-severity cross-site scripting vulnerability in Nagios Log Server, published on 30 Oct 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-36858 in the wild and no public exploit code.

Affected product: Nagios Log Server. 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-2020-36858/ (Markdown: https://insights.sbomify.com/CVE-2020-36858/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-36858
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-36858
- OSV: https://osv.dev/vulnerability/CVE-2020-36858

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-36858/
Summaries are generated and may contain mistakes; the official description above is the record.