CVE-2026-69264

Flowise CSVAgent allows unauthenticated RCE via CSV data URI injection.

• CVSS 9.4
• 94
• Input Validation and Sanitization
• Remote

Prior to 3.1.3, Flowise 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 JavaScript string to js.eval, dynamically import Node built-in modules such as fs and 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 agentflows/chatflows update permission can plant a CSV Agent node with a crafted csvFile; once the chatflow is exposed via POST /api/v1/prediction/:id, any unauthenticated request triggers host remote code execution. This issue is fixed in version 3.1.3.

CVE

CVE-2026-69264

CWE

94

CVSS base score

9.4

Published

2026-08-04

OWASP

A03 Injection

Orthogonal defect classification

Checking

Code defect classification

Missing Check

Category

Input Validation and Sanitization

Subcategory

Command Injection

Accessibility scope

Remote

Impact

Arbitrary Code Execution

Affected component

Flowise

Fixed by upgrading

Yes

Solution

Upgrade Flowise to version 3.1.3 or later.

def get_base64_data_from_uri(uri: str) -> str:
    """Simplified simulation of extracting data from a data URI."""
    if uri.startswith('data:text/csv;base64,'):
        return uri.split(',', 1)[1]
    return ''

def create_csv_agent_code(csv_file_data_uri: str) -> str:
    """
    Generates Python code for the CSVAgent to be run in Pyodide.
    """
    b64_data = get_base64_data_from_uri(csv_file_data_uri)

    # VULNERABLE: Attacker-controlled data is directly formatted into a code template.
    python_code = f"""
import js
import pandas as pd
from io import StringIO
import base64

# The untrusted data is placed inside a string literal, allowing injection.
b64_csv_content = '{b64_data}'

csv_content = base64.b64decode(b64_csv_content).decode('utf-8')
df = pd.read_csv(StringIO(csv_content))
# ... agent logic ...
"""
    return python_code

def get_base64_data_from_uri(uri: str) -> str:
    """Simplified simulation of extracting data from a data URI."""
    if uri.startswith('data:text/csv;base64,'):
        return uri.split(',', 1)[1]
    return ''

def create_csv_agent_code(csv_file_data_uri: str) -> str:
    """
    Generates Python code for the CSVAgent to be run in Pyodide.
    """
    b64_data = get_base64_data_from_uri(csv_file_data_uri)

    # FIX: Input is escaped to prevent an attacker from breaking out of the string literal.
    safe_b64_data = b64_data.replace("\\", "\\\\").replace("'", "\\'")

    python_code = f"""
import js
import pandas as pd
from io import StringIO
import base64

# The data, now sanitized, is safely placed inside the string literal.
b64_csv_content = '{safe_b64_data}'

csv_content = base64.b64decode(b64_csv_content).decode('utf-8')
df = pd.read_csv(StringIO(csv_content))
# ... agent logic ...
"""
    return python_code

data:text/csv,A,B\n', import js; js.eval("import('child_process').then(c => c.execSync('touch /tmp/pwned'))");#

@misc{vaitp:cve202669264,
  title        = {{Flowise CSVAgent allows unauthenticated RCE via CSV data URI injection.}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2026},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2026-69264},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2026-69264/}}
}