# CVE-2026-84189: LibreNMS before 26.7.0 Stored XSS via Oxidized API

> Attackers can inject malicious scripts into LibreNMS via Oxidized API responses, affecting all users viewing device configurations.

- **Severity:** Critical 9.2 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 1 Sep 2026
- **Updated:** 8 Oct 2026
- **Also known as:** GHSA-7gww-x7fh-jf9j, GHSA-r436-6p4j-frwf

## What is CVE-2026-84189?

CVE-2026-84189 is a critical cross-site scripting vulnerability in librenms, published on 1 Sep 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

LibreNMS through 26.4.0 renders JSON fields (name, ip, model, author, commit message) returned by the admin-configurable Oxidized integration URL (oxidized.url) into the device showconfig page without applying htmlspecialchars(). An administrator who points the Oxidized URL at an attacker-controlled server (SSRF) can cause it to return malicious JSON, resulting in stored/persistent cross-site scripting affecting all users who view any device's showconfig tab. Fixed in 26.7.0.

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

## Which versions are affected by CVE-2026-84189?

2 open source packages ship an affected version, including librenms/librenms.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `librenms/librenms` | Packagist | All versions | 26.7.0 |
| `librenms/librenms` | Packagist | All versions | 26.7.0 |

## How do I fix CVE-2026-84189?

Upgrade librenms/librenms to 26.7.0 or later.

## Is CVE-2026-84189 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-84189 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-84189 and fix it if it is affected.

What it is: CVE-2026-84189 is a critical cross-site scripting vulnerability in librenms, published on 1 Sep 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-84189 exists.

Affected packages and fixed versions:
- librenms/librenms (Packagist): affected all versions; fixed in 26.7.0
- librenms/librenms (Packagist): affected all versions; fixed in 26.7.0

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-2026-84189/ (Markdown: https://insights.sbomify.com/CVE-2026-84189/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-84189
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-84189
- OSV: https://osv.dev/vulnerability/CVE-2026-84189

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-84189/
Summaries are generated and may contain mistakes; the official description above is the record.