GHSA-j8cq-7f6p-256x
MEDIUMLibreNMS vulnerable to Reflected Cross-Site Scripting (XSS) in endpoint `/maps/nodeimage` parameter `Image Name`
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
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Description
Summary
A Reflected Cross-Site Scripting (XSS) vulnerability was identified in the LibreNMS application at the /maps/nodeimage endpoint. The Image Name parameter is reflected in the HTTP response without proper output encoding or sanitization, allowing an attacker to craft a URL that, when visited by a victim, causes arbitrary JavaScript execution in the victim’s browser.
Details
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Vulnerable Endpoint:
GET /maps/nodeimage -
Parameter:
Image Name(reflected in response) -
Vulnerability type: Reflected Cross-Site Scripting (XSS) — input is reflected in server response and executed in victim browser.
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CWE: CWE-79 (Improper Neutralization of Input During Web Page Generation — Cross-site Scripting)
Description
The application takes the value of the Image Name parameter from a request to /maps/nodeimage and includes it in the generated page or response without proper contextual encoding. Because the input is reflected immediately back to the client and parsed as HTML/JavaScript by the browser, an attacker can craft a URL containing a malicious script. If a victim (for example, an authenticated user or administrator) is tricked into visiting that URL, the injected script will execute in the victim’s browser context.
Proof of Concept (PoC)
Construct a request that includes the following payload in the Image Name parameter. The payload below should be used exactly as provided:
<script>alert('PoC-XXS51')</script>
Steps to reproduce
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Authenticate as any user allowed to manage Node Images;
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Navigate the endpoint '/maps/nodeimage' and click on "New Image". Choose any valide image and, on
Image Nameparameter, insert the payload above .
- Observe the server response page; if vulnerable, the payload will be executed by the browser and an alert box with
PoC-XXS51will appear.
Observed behavior
The supplied payload is reflected in the HTTP response and interpreted by the browser, resulting in immediate execution (demonstrated by an alert popup). This confirms the application does not perform appropriate output encoding for the Image Name parameter.
Impact
Reflected XSS can be used to:
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Execute arbitrary JavaScript in the context of any user who visits the crafted link.
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Steal session cookies or authentication tokens (leading to session hijacking).
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Perform actions on behalf of the victim (CSRF-like actions executed via script).
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Phish users by manipulating the page UI, or exfiltrate sensitive information visible to the victim.
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Pivot to further attacks depending on application context and user privileges.
References
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CWE-79 — Cross-Site Scripting (XSS).
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OWASP XSS Prevention Cheat Sheet.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | librenms/librenms | all versions | 25.11.0 |
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 25.11.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j8cq-7f6p-256x 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-j8cq-7f6p-256x 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-j8cq-7f6p-256x. 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-j8cq-7f6p-256x in your dependencies?
O3 detects GHSA-j8cq-7f6p-256x across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.