by Kastro
Paper/Archive/CVE-2026-56271

CVE-2026-56271

Flowise Flowise — Flowise - Weak Default JWT Secrets in Authentication Middleware

EPSS 0.7%CVSS 9.8
critical.is priorityof 100
40
CVSS 9.8 (CNA)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 51.4.514 × 2010.3No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
Flowise< 3.1.03.1.0CNA

Scores by source

VulnCheck (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
VulnCheck (CNA)9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

advisorygithub.com/FlowiseAI/Flowise/security/advisories/GHSA-cc4f-hjpj-g9p8writeupvulncheck.com/advisories/flowise-weak-default-jwt-secrets-in-authentication-middleware