Executive brief
Flowise, an open-source tool for building LLM applications, contains a flaw in how it handles billing and subscription updates. An attacker with a valid account can modify the Stripe subscription details of other organizations by providing a victim's subscription ID. This could lead to unauthorized charges, service downgrades, or financial disruption for affected customers.
Technical details
Flowise suffers from an Insecure Direct Object Reference (IDOR) / Broken Access Control vulnerability in the `update-additional-seats` and `update-subscription-plan` routes within `organization.route.ts`. The server accepts a `subscriptionId` directly from the request body and processes billing changes via the Stripe integration without verifying if the subscription belongs to the authenticated user's organization. An attacker can obtain a victim's `subscriptionId` through other API endpoints and then issue POST requests to modify seat quantities or change subscription plans. This issue is fixed in version 3.1.3.
Affected products
- FlowiseAI flowise <= 3.1.2
Timeline
- 2026-07-29: disclosed
- 2026-08-04: advisory
- 2026-08-04: patched
References
- https://api.github.com/users/berkdedekarginoglu
- https://github.com/berkdedekarginoglu
- https://api.github.com/users/berkdedekarginoglu/gists%7B/gist_id%7D
- https://api.github.com/users/berkdedekarginoglu/repos
- https://avatars.githubusercontent.com/u/30373481?v=4
- https://api.github.com/users/berkdedekarginoglu/events%7B/privacy%7D