CVE-2026-56672
HighCVSS 8.2Exploitation Probability (EPSS)
Low risk15th percentile - higher than 15% of all known CVEs
Summary
ComfyUI prior to version 0.28.0 is vulnerable to stored cross-site scripting (XSS) in the GET /userdata/{file} endpoint. It serves user-controlled HTML and SVG files with extension-derived content types, allowing script execution in the ComfyUI origin and access to API tokens, settings, workflows, and authenticated-equivalent API calls.
Risk Assessment
An attacker can steal API tokens and credentials stored in the victim's browser, leading to full account compromise in ComfyUI.
Recommendation
Update ComfyUI to version 0.28.0 or later.
Other vulnerabilities in ComfyUI
See all- CVE-2026-68771Critical
ComfyUI v0.23.0 contains an unsafe deserialization vulnerability in the LoadTrainingDataset node. An unauthenticated attacker can upload a crafted pickle file via the POST /upload/image endpoint and trigger its deserialization via POST /prompt, leading to arbitrary Python code execution through torch.load.
- CVE-2026-56673High
ComfyUI prior to version 0.28.0 is vulnerable in folder_paths.get_annotated_filepath and exists_annotated_filepath. They join workflow-controlled filenames to a base directory without containment check, allowing an unauthenticated attacker to craft a POST /prompt request using LoadImage or similar nodes to probe arbitrary host paths and exfiltrate image-format files through /view.
- CVE-2026-56671High
ComfyUI prior to version 0.28.0 is vulnerable in the get_model_preview function in app/model_manager.py. It joins an unrestricted filename to a selected model directory without containment check, allowing an unauthenticated attacker to use traversal, absolute paths, or an unbounded path_index to read image-decodable files and enumerate host paths.
- CVE-2026-56670High
ComfyUI prior to version 0.28.0 is vulnerable to stored cross-site scripting (XSS) in the /view endpoint. It serves uploaded SVG files inline because image/svg+xml and related content types were not handled as dangerous, allowing script execution in the ComfyUI origin.
Original NVD description (English source)
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.