Python validator Unicode homoglyph bypass in Flowise (CVE-2026-70470)

The `validatePythonCodeForDataFrame` function in Flowise's `pythonCodeValidator.ts` enforces a JavaScript regex blacklist against dangerous Python identifiers, but JavaScript word-boundary anchors (`\b`) are ASCII-only while Python 3 NFKC-normalizes Unicode identifiers at parse time, allowing homoglyph substitutions such as `__cl𝐚ss__` and `__b𝐮iltins__` to pass validation undetected. An attacker who can supply Python code to the CSV Agent or Airtable Agent can exploit this bypass to execute arbitrary Python inside Pyodide and, via Pyodide's js module interop with the Node.js host, run native OS commands on the Flowise server with the privileges of the Flowise process. Affected versions: - npm flowise <= 3.1.2 - npm flowise-components <= 3.1.2 We recommend updating to: npm flowise 3.1.3, npm flowise-components 3.1.3. CVSS 9.5 · our assessment: act_now Reference: https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-52fh-8v99-63c2 Details: https://vuln.today/cve/CVE-2026-70470