CVE-2026-70474

Flowise before 3.1.3 exposes three OAuth2 credential endpoints (authorize, callback, and refresh under /api/v1/oauth2-credential/) that look up credentials by id alone with no workspaceId filter, and the callback and refresh routes are whitelisted from authentication. An authenticated low-privileged user can initiate OAuth2 flows against credentials belonging to other workspaces, while an unauthenticated attacker who knows or guesses a credential id can forge an OAuth2 callback to overwrite the stored tokens in any credential, or call refresh to obtain refreshed tokens for any credential. Successful abuse allows cross-tenant credential tampering and token hijacking, potentially compromising the third-party services and integrations connected via those credentials. All Flowise deployments prior to 3.1.3 are affected, with the greatest risk to multi-workspace/shared instances and instances exposed to the internet. No in-the-wild exploitation is confirmed; EPSS is low (0.3%, ~23rd percentile), it is not in CISA KEV, and one public advisory reference (GHSA-wch5-xp77-fxg4) exists.

What to do: Upgrade Flowise to version 3.1.3 or later immediately. As interim mitigation, restrict access to the /api/v1/oauth2-credential/authorize, /callback, and /refresh routes at a reverse proxy or WAF to trusted clients only, and review the Credential table and OAuth-connected integrations for unexpected token changes or refresh activity.