Lines 133-138 — Unsanitized string extraction from data URI via file.split(',').pop().pop() — no validation on content.
Lines 155-171 — Direct interpolation into executable Python code:
base64_string = "${base64String}" is inserted into a Python string literal via JS template literal. If the string contains a closing double-quote followed by Python code, it breaks out of the string context.
validatePythonCodeForDataFrame() denylist is only applied to LLM-generated code at line 198, NOT to this initial code block at line 171.
Remediation
Option 1 (Best): Use pyodide.globals.set('base64_string', base64String) instead of string interpolation
Option 2: Validate base64 before interpolation — reject if not matching /^[A-Za-z0-9+/=]*$/
Option 3: Escape special characters (", \n, \r, \\) before interpolation
Related CVEs
CVE-2026-41264 (CSV Agent regex bypass)
CVE-2026-41265 (Airtable Agent sandbox bypass)
CVE-2026-46442 (NodeVM sandbox escape)
Disclosure: Identified with AI assistance (Claude Code). Analysis, verification, and Metasploit module by S9S Bounty-LAB / Kamal Sentassi.