Advisory details:
github_osv / GHSA-qgvm-j2hm-6m38
| Advisory ID | github_osv/GHSA-qgvm-j2hm-6m38 |
| Aliases |
CVE-2026-70478
|
| Summary | 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 ```typescript // 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 1. Attacker obtains a credential ID (via Finding 2 / public chatflow leak, or enumeration) 2. Attacker calls `POST /api/v1/oauth2-credential/refresh/:credentialId` (no auth required) 3. Server decrypts credential, sends refresh request to OAuth provider with user's `client_secret` 4. Server returns the new `access_token` in the response to the attacker 5. 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: ```typescript // Remove from WHITELIST_URLS in constants.ts // Add authentication check in the route handler ``` --- ## Credits - Shinobi Security - https://github.com/shinobisecurity |
| Status | Published |
| Exploitability | 0.5 |
| Weighted Severity | 8.3 |
| Risk | 4.2 |
| Affected and Fixed Packages | Package Details |
| Introduced and Fixed Package Commit Patches | Package Commit Patches Details |
| System | Score | Found at |
|---|---|---|
| cvssv4 | 9.2 | https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-qgvm-j2hm-6m38/GHSA-qgvm-j2hm-6m38.json |
| generic_textual | CRITICAL |
| Reference id | Reference type | URL |
|---|---|---|
| https://github.com/FlowiseAI/Flowise | ||
| https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-qgvm-j2hm-6m38 |
No EPSS data available for this advisory.
| Patch URL | |
|---|---|
| There are no known patches. | |
| Attack Vector (AV) | Attack Complexity (AC) | Attack Requirements (AT) | Privileges Required (PR) | User Interaction (UI) | Vulnerable System Impact Confidentiality (VC) | Vulnerable System Impact Integrity (VI) | Vulnerable System Impact Availability (VA) | Subsequent System Impact Confidentiality (SC) | Subsequent System Impact Integrity (SI) | Subsequent System Impact Availability (SA) |
|---|---|---|---|---|---|---|---|---|---|---|
network adjacent local physical |
low high |
none present |
none low high |
none passive active |
high low none |
high low none |
high low none |
high low none |
high low none |
high low none |
Vector: SSVCv2/E:P/A:Y/T:P/P:M/B:A/M:M/D:T/2026-08-05T19:05:05Z/
Decision: Track
Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/70xxx/CVE-2026-70478.json
Source Advisory: vulnrichment/CVE-2026-70478
[{'Exploitation': 'poc'},
{'Automatable': 'yes'},
{'Technical Impact': 'partial'},
{'Mission Prevalence': 'minimal'},
{'Public Well-being Impact': 'material'},
{'Mission & Well-being': 'medium'}]