CVE-2026-69264: Flowise: RCE via CSVAgent csvFile data URI base64 segment is interpolated into Python source without validation

Flowise’s CSVAgent interpolates an attacker-controlled segment of the csvFile data URI directly into a Python source-code template that is then executed by Pyodide. Because Pyodide is loaded with the default js bridge to globalThis (which on Node.js exposes eval and dynamic import()), the attacker can break out of the Python string literal, hand a JS string to js.eval, dynamically import any Node built-in module (fs, child_process, …), and execute arbitrary file I/O or OS commands as the Flowise process. The two validator paths around this code (validatePythonCodeForDataFrame and validateCustomReadCSVFunction) are never applied to the bootstrap template.

A workspace user with chatflows:create (or any agentflows/chatflows update permission) plants a CSV Agent node with a crafted csvFile. Once the chatflow is exposed via the (whitelisted, public) POST /api/v1/prediction/:id endpoint, any unauthenticated request triggers the host RCE.