CVE-2026-56672 — ComfyUI is a node-based diffusion model GUI, API, and backend.¶
Key facts
CVE-2026-56672 is a High (8.2) vulnerability: ComfyUI is a node-based diffusion model GUI, API, and backend.. This entry ships a detection-only PoC and a Docker test lab.
| CVE | CVE-2026-56672 |
| Severity | High (8.2) |
| Detection / prevention | — |
| PoC | poc.py |
| Source | 2026/CVE-2026-56672/ |
Details¶
English | 한국어
Description¶
ComfyUI is a node-based diffusion model GUI, API, and backend. Prior to 0.28.0, GET /userdata/{file} served user-controlled HTML and SVG files with extension-derived content types, allowing stored cross-site scripting in the ComfyUI origin and access to browser-stored API tokens, settings, workflows, and authenticated-equivalent API calls. The handler used web.FileResponse(path), so an uploaded .html/.svg was served as text/html/image/svg+xml. POST /userdata stores arbitrary request bodies (confined to the user's userdata directory). When a victim navigated to the file URL, the embedded script executed same-origin. The /view endpoint already forced dangerous MIME types to download; that protection had never been applied to /userdata. This issue is fixed in version 0.28.0.
Vulnerability Details¶
| Property | Value |
|---|---|
| CVE ID | CVE-2026-56672 |
| Type | XSS |
| CVSS Score | 8.2 |
Proof of Concept¶
Download¶
# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-56672/poc.py
Usage¶
# Run PoC against target
python3 poc.py --target <TARGET_URL>
# With authentication
python3 poc.py --target <TARGET_URL> --username <USER> --password <PASS>
⚠️ Warning: This PoC is for authorized security testing only. It uses detection-only techniques and does not exploit or damage target systems.
Test Lab¶
This repository includes a Docker-based test environment with both vulnerable and patched applications.
Quick Start¶
# Clone and navigate to CVE directory
cd CVE-2026-56672
# Start both applications
docker-compose up -d
# Run tests
./run-tests.sh # Linux/Mac
./run-tests.ps1 # Windows PowerShell
Application Endpoints¶
| Application | URL | Status |
|---|---|---|
| Vulnerable App | http://localhost:8080 | Shows vulnerability |
| Patched App | http://localhost:8081 | Demonstrates fix |
Directory Structure¶
├── README.md # English documentation
├── README_KO.md # Korean documentation
├── poc.py # PoC detection script
├── docker-compose.yml # Container orchestration
├── run-tests.sh # Linux/Mac test runner
├── run-tests.ps1 # Windows test runner
├── vulnerable-app/ # Vulnerable version
│ ├── app.py
│ ├── Dockerfile
│ └── requirements.txt
└── patched-app/ # Fixed version
├── app.py
├── Dockerfile
└── requirements.txt
References¶
- https://github.com/Comfy-Org/ComfyUI/commit/96e0e3585b41e1417442eaa14ec57f7b4ffcb5e0
- https://github.com/Comfy-Org/ComfyUI/releases/tag/v0.28.0
- https://github.com/Comfy-Org/ComfyUI/security/advisories/GHSA-53g8-45wq-pcv8
Generated by PoC Generator on 2026-08-01T21:34:00.690128976
Frequently asked questions¶
What is CVE-2026-56672?¶
CVE-2026-56672 is a High (8.2) vulnerability: ComfyUI is a node-based diffusion model GUI, API, and backend.. This entry ships a detection-only PoC and a Docker test lab.
How do I detect CVE-2026-56672?¶
Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.
How do I block or mitigate CVE-2026-56672?¶
Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.
For authorized security testing and research only. See the full source and NVD record.