Flowise Hardcoded Default JWT Secrets Authentication Bypass

Technical Analysis

The enterprise passport authentication middleware (packages/server/src/enterprise/middleware/passport/index.ts) reads JWT_AUTH_TOKEN_SECRET, JWT_REFRESH_TOKEN_SECRET, JWT_AUDIENCE, and JWT_ISSUER from environment variables, but silently falls back to hardcoded literals ('auth_token', 'refresh_token', 'AUDIENCE', 'ISSUER') if they are unset, with no warning or hard failure. Because these values are public (visible in the open-source codebase), an attacker can craft a JWT signed with the known secret and matching audience/issuer claims, and the middleware will validate it as legitimate, granting arbitrary session and role claims including admin privileges. The entry point is any exposed Flowise enterprise deployment with default configuration; exploitation requires no prior authentication, only knowledge of the public default secret and the target's API endpoint. Once authenticated as admin, the attacker gains full control over agent workflows, credentials stored in the platform, connected tool integrations, and any downstream systems those agents can reach, effectively crossing from a platform-level auth flaw into full agentic-pipeline compromise.

Affected Systems

Flowise

Detection Signatures

• Deployment config missing JWT_AUTH_TOKEN_SECRET, JWT_REFRESH_TOKEN_SECRET, JWT_AUDIENCE, or JWT_ISSUER environment variables
• JWT tokens observed with iss=ISSUER or aud=AUDIENCE claim values
• JWT tokens verifiable/signed using the literal strings 'auth_token' or 'refresh_token' as HMAC secret
• Unexpected admin-level API access from unfamiliar source IPs shortly after Flowise deployment
• Absence of startup warning/error when JWT env vars are unset (indicates vulnerable version)

Remediation Steps

1. 1

   Upgrade Flowise

   Update to Flowise 3.1.0 or later, which addresses this hardcoded secret fallback issue.

2. 2

   Set strong unique secrets

   Explicitly configure JWT_AUTH_TOKEN_SECRET, JWT_REFRESH_TOKEN_SECRET, JWT_AUDIENCE, and JWT_ISSUER with cryptographically strong, unique, environment-specific values before deployment.

3. 3

   Fail closed on missing config

   Modify or patch deployments so the application refuses to start or rejects auth entirely if required JWT secrets are not explicitly set, rather than silently using defaults.

4. 4

   Rotate credentials and audit access

   Rotate all JWT secrets and review authentication logs for signs of forged tokens or unauthorized admin access following upgrade.

5. 5

   Restrict network exposure

   Limit access to the Flowise enterprise admin interface to trusted networks/VPN until patched and reconfigured.