Executive brief
TypeBot is a chatbot builder that allows users to configure custom domains for their chatbots. Prior to version 3.18.0, any authenticated workspace member could delete another workspace's custom domain, making all chatbots on that domain unavailable. This is an authorization flaw where the system verified which workspace the attacker belonged to, but failed to verify that the domain being deleted actually belonged to that workspace.
Technical details
The vulnerability is an authorization bypass in the custom domain deletion handler (handleDeleteCustomDomain.ts). The vulnerable code authorized the caller against a client-supplied workspaceId, but then sent the client-supplied domain name directly to the Vercel provider without verifying that the domain belonged to the verified workspace. An authenticated non-guest workspace member can exploit this by crafting a deletion request specifying another workspace's domain, causing that domain to be removed from the shared provider. The fix, deployed in version 3.18.0, adds a scoped custom domain lookup to verify ownership before deletion and uses the verified domain name for provider and database deletion operations.
Affected products
- TypeBot TypeBot before 3.18.0
Timeline
- 2026-08-25: disclosed
- 2026-06-27: patched: Fix commit merged, released in v3.18.0 on 2026-08-21