CVE-2026-70478: Flowise: Unauthenticated OAuth2 token refresh endpoint returns access tokens — enables token theft for any connected service

August 4, 2026

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.

References

github.com/FlowiseAI/Flowise/security/advisories/GHSA-qgvm-j2hm-6m38
github.com/advisories/GHSA-qgvm-j2hm-6m38
nvd.nist.gov/vuln/detail/CVE-2026-70478

Code Behaviors & Features

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