Executive brief
Budibase is a low-code platform that allows builders to create applications and automate workflows. When an SSO-authenticated builder tests an automation, their OAuth2 access and refresh tokens are exposed to all other builders of the same app through WebSocket broadcasts and a test status API endpoint. An attacker with builder access to the same app can steal these tokens to access the victim's external service accounts (Google, Azure AD, GitHub, etc.) indefinitely, even after the original tokens expire.
Technical details
This is an information disclosure vulnerability in the automation test pipeline. The root cause is that OAuth2 tokens are intentionally included in user context bindings passed to automations (so they can call external APIs), but the full result—including these sensitive tokens—is broadcast via WebSocket to all builders in the app room and stored in an in-memory cache queryable by any builder via GET /api/automations/:id/test/status. No user isolation or sanitization is applied. Attack requires builder-level access to the same app and that a co-builder authenticates via SSO/OIDC. The attacker can passively receive tokens by keeping the builder UI open, or actively poll the test status endpoint. Tokens remain accessible for 5 minutes. Patched in version 3.40.0 with sanitization of OAuth2 tokens from test results before broadcast/storage.
Affected products
- Budibase @budibase/server <3.40.0
Timeline
- 2026-07-24: disclosed
- 2026-07-22: patched: Version 3.40.0