Budibase: Workspace-scoped builder escalates to global admin via /api/public/v1/roles/assign

Budibase is an open-source low-code platform. Prior to 3.39.0, /api/public/v1/roles/assign is guarded by the builderOrAdmin middleware, which passes any user who is a builder for the app id in the x-budibase-app-id header. That check admits both global builders and workspace-scoped builders (builder.apps set but builder.global unset). The controller then spreads the request body into the SDK call, and the SDK grants builder.global=true or admin.global=true on whichever user ids the caller supplies. Bob, a workspace-scoped builder with an API key, promotes himself or any other user to global admin with one POST. The whole flow is tenant-wide privilege escalation from an app-level role, available to anyone with an Enterprise license that unlocks the EXPANDED_PUBLIC_API feature. This vulnerability is fixed in 3.39.0.