CVE-2026-70478 — flowise
CVE-2026-70478 is a Information Exposure vulnerability in flowise. A fix is available for flowise — see the affected versions and patch details below.
Flowise: Unauthenticated OAuth2 token refresh endpoint returns access tokens — enables token theft for any connected service
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.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-70478.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
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
Summary
The OAuth2 token refresh endpoint (POST /api/v1/oauth2-credential/refresh/:credentialId) is in WHITELIST_URLS, meaning it requires no authentication. It decrypts the stored credential (containing clientId, clientSecret, refresh_token), sends a refresh request to the configured OAuth provider, and returns the new access_token directly in the response body.
Root Cause
// packages/server/src/routes/oauth2/index.ts:393-402
res.json({
success: true,
message: 'OAuth2 token refreshed successfully',
credentialId: credential.id,
tokenInfo: {
...tokenData, // ← includes access_token!
has_new_refresh_token: !!tokenData.refresh_token,
expires_at: updatedCredentialData.expires_at
}
})
Whitelist entry at packages/server/src/utils/constants.ts:40.
Attack Chain
- Attacker obtains a credential ID (via Finding 2 / public chatflow leak, or enumeration)
- Attacker calls
POST /api/v1/oauth2-credential/refresh/:credentialId(no auth required) - Server decrypts credential, sends refresh request to OAuth provider with user's
client_secret - Server returns the new
access_tokenin the response to the attacker - Attacker uses the token to access the victim's connected service (Google, Microsoft, etc.)
Docker Validation
POST /api/v1/oauth2-credential/refresh/fake-uuid returns {"message":"Credential not found"} (not 401 Unauthorized), proving the endpoint processes the request without authentication.
Impact
- OAuth2 access token theft for any connected service
- Full access to the victim's third-party accounts (Google, Microsoft, GitHub, etc.)
- Client secret transmitted to OAuth provider during refresh
- Can also be used for DoS by exhausting refresh token quota
Suggested Fix
Remove the refresh endpoint from WHITELIST_URLS and require authentication:
// Remove from WHITELIST_URLS in constants.ts
// Add authentication check in the route handler
Credits
- Shinobi Security - https://github.com/shinobisecurity
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | flowise | all versions | 3.1.3npm install flowise@3.1.3 |
Affected Products
flowiseflowiseaiDetection & 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 3.1.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-70478 is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.
Frequently Asked Questions
Is CVE-2026-70478 in your dependencies?
Find it across npm, including transitive dependencies.