CVE-2026-70478
Flowise: Unauthenticated OAuth2 token refresh endpoint returns access tokens — enables token theft for any connected service
Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.3, the POST /api/v1/oauth2-credential/refresh/:credentialId endpoint is included in WHITELIST_URLS and requires no authentication. The endpoint decrypts the stored credential, sends a refresh request to the configured OAuth provider with the client secret and refresh token, and returns the refreshed access_token in the response body. An attacker with a credential ID can use the token to access the victim's connected service and can also exhaust refresh-token quota. This issue is fixed in 3.1.3.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
9.2
Flowise: Unauthenticated OAuth2 token refresh endpoint returns access tokens — enables token theft for any connected service
Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.3, the POST /api/v1/oauth2-credential/refresh/:credentialId endpoint is included in WHITELIST_URLS and requires no authentication. The endpoint decrypts the stored credential, sends a refresh request to the configured OAuth provider with the client secret and refresh token, and returns the refreshed access_token in the response body. An attacker with a credential ID can use the token to access the victim's connected service and can also exhaust refresh-token quota. This issue is fixed in 3.1.3.
- Record
CVE-2026-70478- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N - Weakness
- CWE-200
- Updated
- 2026-11-02
EUVDEUVD-2026-52912
9.2
Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.3, the POST /api/v1/oauth2-credential/refresh/:credentialId endpoint is included in WHITELIST_URLS and requires no authentication. The endpoint decrypts the stored credential, sends a refresh request to the configured OAuth provider with the client secret and refresh token, and returns the refreshed access_token in the response body. An attacker with a credential ID can use the token to access the victim's connected service and can also exhaust refresh-token quota. This issue is fixed in 3.1.3.
- Record
EUVD-2026-52912- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-qgvm-j2hm-6m38
9.2
Flowise: Unauthenticated OAuth2 token refresh endpoint returns access tokens — enables token theft for any connected service
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
- Record
GHSA-qgvm-j2hm-6m38- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N - Weakness
- CWE-200
- Updated
- 2026-11-02
NVD
9.2
Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.3, the POST /api/v1/oauth2-credential/refresh/:credentialId endpoint is included in WHITELIST_URLS and requires no authentication. The endpoint decrypts the stored credential, sends a refresh request to the configured OAuth provider with the client secret and refresh token, and returns the refreshed access_token in the response body. An attacker with a credential ID can use the token to access the victim's connected service and can also exhaust refresh-token quota. This issue is fixed in 3.1.3.
- Record
CVE-2026-70478- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-200
- Updated
- 2026-11-02
OSV
9.2
Flowise: Unauthenticated OAuth2 token refresh endpoint returns access tokens — enables token theft for any connected service
Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.3, the POST /api/v1/oauth2-credential/refresh/:credentialId endpoint is included in WHITELIST_URLS and requires no authentication. The endpoint decrypts the stored credential, sends a refresh request to the configured OAuth provider with the client secret and refresh token, and returns the refreshed access_token in the response body. An attacker with a credential ID can use the token to access the victim's connected service and can also exhaust refresh-token quota. This issue is fixed in 3.1.3.
- Record
CVE-2026-70478- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N - Weakness
- CWE-200
- Updated
- 2026-11-02
OSVGHSA-qgvm-j2hm-6m38
9.2
Flowise: Unauthenticated OAuth2 token refresh endpoint returns access tokens — enables token theft for any connected service
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
- Record
GHSA-qgvm-j2hm-6m38- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N - Weakness
- CWE-200
- Updated
- 2026-11-02
Affected products
Affected packages
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-70478 is a critical vulnerability (CVSS 9.2) in Flowiseai Flowise, published August 4, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.61%, the 49th percentile. Fixed in flowise 3.1.3.