What is this vulnerability?

Flowise before 3.1.0 (affected versions 3.0.13 and earlier) uses weak hardcoded default JWT secrets ('auth_token', 'refresh_token') and default audience and issuer values ('AUDIENCE', 'ISSUER') in the enterprise passport authentication middleware (packages/server/src/enterprise/middleware/passport/index.ts). When the corresponding environment variables (JWT_AUTH_TOKEN_SECRET, JWT_REFRESH_TOKEN_SECRET, JWT_AUDIENCE, JWT_ISSUER) are not set, the application silently falls back to these publicly known defaults, allowing an attacker to forge valid JWTs and impersonate any user, including administrators, resulting in authentication bypass.

How it works

This is classified as CWE-321. In plain terms, an attacker could use this flaw in the affected product to gain access, disrupt service, or steal data — the exact impact depends on how it’s deployed in your environment.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Mitigations

• Apply the vendor’s security patch or update as soon as it’s available and tested.
• If no patch exists yet, apply the vendor’s temporary workaround.
• Limit network exposure of the affected system until it’s patched.
• Track the vendor advisory — disclosed vulnerabilities can move to active exploitation quickly.

Recommendations

• Confirm whether this vendor’s affected product is used anywhere in your environment.
• Patch internet-facing systems first, then internal ones.
• Prioritise by exposure and exploitability while a fix is scheduled.
• Subscribe to the vendor’s security advisories for earlier warning next time.