CVE-2026-6592
Cross-Site Scripting in ComfyUI userdata Endpoint (Remote
Publication date: 2026-04-20
Last updated on: 2026-04-29
Assigner: VulDB
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| comfyui | comfyui | to 0.13.0 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-79 | 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. |
| CWE-94 | The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in ComfyUI up to version 0.13.0, specifically in the getuserdata function within the app/user_manager.py file of the userdata Endpoint component.
The issue allows an attacker to perform cross-site scripting (XSS) attacks by manipulating this function.
The attack can be executed remotely, meaning an attacker does not need local access to exploit it.
The vulnerability has been publicly disclosed and the vendor did not respond to the notification.
How can this vulnerability impact me? :
This vulnerability can lead to cross-site scripting attacks, which may allow attackers to execute malicious scripts in the context of the affected application.
Such attacks can result in the theft of user session tokens, defacement of the website, or redirection to malicious sites.
Since the attack can be performed remotely, it increases the risk of exploitation without requiring physical or internal network access.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The vulnerability allows attackers to execute stored cross-site scripting (XSS) attacks by uploading malicious files that execute JavaScript in the context of the ComfyUI origin.
This enables attackers to access and steal sensitive data stored in the victim’s localStorage, including workflows, settings, and session data, and perform arbitrary API calls on behalf of the victim.
Such unauthorized access and potential data exfiltration could lead to violations of data protection regulations like GDPR and HIPAA, which require safeguarding personal and sensitive information against unauthorized access and breaches.
Therefore, this vulnerability poses a risk to compliance with these common standards and regulations by potentially exposing sensitive user data and compromising application integrity.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by testing the /userdata/{file} endpoint for the ability to upload and serve files with unsafe MIME types that allow script execution, such as .html or .svg files containing JavaScript.
A practical approach is to upload a malicious HTML file containing JavaScript via a POST request and then access the uploaded file to verify if the script executes.
Example commands to detect the vulnerability include:
- Upload a test HTML file with embedded JavaScript using curl: curl -X POST "http://127.0.0.1:8188/userdata/test_xss.html" -d '<html><body><script>alert(document.domain)</script></body></html>'
- Access the uploaded file in a browser to check if the JavaScript executes.
- Verify the Content-Type header returned by the server using curl: curl -D - "http://127.0.0.1:8188/userdata/test_xss.html"
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation steps include restricting or disabling the ability to upload files to the /userdata endpoint, especially files with extensions that can be interpreted as executable scripts such as .html and .svg.
Implement Content-Type sanitization on the /userdata endpoint similar to the /view endpoint by forcing dangerous MIME types to application/octet-stream to prevent script execution.
Until a patch is available, consider restricting access to the /userdata endpoint to trusted users only or disabling the endpoint if possible.
Monitor and audit uploaded files for suspicious content and remove any files that could be exploited.