CVE-2026-46476

## Summary **Type:** Mass assignment via `Object.assign(entity, body)` -> client-controlled `workspaceId` (and on create, `id`) overwritten on the CustomTemplate entity -> cross-workspace data takeover and IDOR. **File:** `packages/server/src/services/marketplaces/index.ts` **Root cause:** The CustomTemplate controller/service constructs a `new CustomTemplate()` and copies the request body into it via `Object.assign(...)` without an explicit field allowlist. The request body therefore can include `workspaceId`, `id`, `createdDate`, `updatedDate`. The server only rebinds *some* of these after the assign (e.g. on create, it overwrites `workspaceId` but not `id`; on update, it overwrites `id` but not `workspaceId`). The remaining client-controlled values land directly on the persisted row, breaking workspace isolation. Same root pattern as the customtemplate entity's sibling controllers and as `DocumentStore` before it was patched in commit 840d2ae. ## Affected Code **File:** `packages/server/src/services/marketplaces/index.ts` ```ts // at line 211 Object.assign(newTemplate, body) // <-- BUG: body.id, body.workspaceId accepted ``` **Why it's wrong:** `Object.assign(target, source)` copies every own enumerable property of `source` onto `target`. The TypeORM/SQL persistence layer below it does not strip ownership-bearing columns, so `workspaceId` set in the request body lands as the new `workspaceId` of the persisted row. The DocumentStore patch (commit 840d2ae) demonstrated the intended fix shape (explicit field-by-field allowlist) but it has not been applied to this entity. ## Exploit Chain 1. Attacker is an authenticated member of workspace A. They have a session cookie / JWT for the Flowise web UI. State at this point: attacker can read and write entities scoped to workspace A. 2. Attacker creates a customtemplate in workspace A via the documented API (or reuses an existing one they own). They note its entity `id`. 3. Attacker issues a `PUT /api/v1/cust