{"id":"CVE-2026-56672","title":"ComfyUI is a node-based diffusion model GUI, API, and backend","summary":"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 orig…","severity":"high","cvss":8.2,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N","cwe":["CWE-79"],"published":"2026-07-31","updated":"2026-09-08","sourceUpdated":"2026-09-08T20:41:31.497","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-56672","references":[{"url":"https://github.com/Comfy-Org/ComfyUI/commit/96e0e3585b41e1417442eaa14ec57f7b4ffcb5e0","label":"security-advisories@github.com"},{"url":"https://github.com/Comfy-Org/ComfyUI/releases/tag/v0.28.0","label":"security-advisories@github.com"},{"url":"https://github.com/Comfy-Org/ComfyUI/security/advisories/GHSA-53g8-45wq-pcv8","label":"security-advisories@github.com"}],"tags":["nvd"],"epss":0.00397,"epssPercentile":0.31039,"ingestedAt":"2026-09-08T21:11:12.260Z","slug":"CVE-2026-56672","body":"## Overview\n\nComfyUI 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":45.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}