GHSA-4672-hwv6-gq62

### Summary

Trigger.dev isolates each project into multiple **environments** (`dev`, `staging`, `prod`, and per-PR `preview` branches), each with its **own secret API key** — the environment is a trust boundary (a `dev`/preview/CI key is lower-trust than a `prod` key). Most API routes enforce this by scoping resource lookups to the authenticated key's environment (`where: { friendlyId, runtimeEnvironmentId: auth.environment.id }`).

The deployment **cancel** path does not. `DeploymentService.getDeployment()` scopes the lookup by **`projectId` only** — never `environmentId` — so a secret key for *any* environment in a project can cancel a deployment belonging to *any other* environment of the same project, including **production**. The deployment **GET** route, by contrast, *is* env-scoped — so the same key that is **404'd when trying to read** a prod deployment can nonetheless **cancel** it. That asymmetry is the bug.

### Affected

`apps/webapp`, HEAD `5d99457` (current `main`). Affects self-hosted and cloud.

### Root cause

`apps/webapp/app/routes/api.v1.deployments.$deploymentId.cancel.ts` authenticates to an environment and calls `deploymentService.cancelDeployment(authenticatedEnv, deploymentId, ...)`.

`apps/webapp/app/v3/services/deployment.server.ts`: ```ts public cancelDeployment(authenticatedEnv: Pick<AuthenticatedEnvironment,"projectId">, friendlyId, ...) { return this.getDeployment(authenticatedEnv.projectId, friendlyId) // projectId only .andThen(validateDeployment) // rejects only FINAL statuses .andThen(cancelDeployment); // updateMany -> status CANCELED } private getDeployment(projectId: string, friendlyId: string) { return this._prisma.workerDeployment.findFirst({ where: { friendlyId, projectId }, // <-- NO environmentId filter }); } ```

`cancelDeployment` accepts `authenticatedEnv` but its type is literally `Pick<AuthenticatedEnvironment,"projectId">` — it discards the environment identity. `validateDeployment` blocks only `FINAL_DEPLOYMENT_STATUSES`, so any in-progress deployment (`PENDING`/`INSTALLING`/`BUILDING`/`DEPLOYING`) is cancellable.

**Contrast — the correctly env-scoped sibling** `api.v1.deployments.$deploymentId.ts` (GET): ```ts const deployment = await prisma.workerDeployment.findFirst({ where: { friendlyId: deploymentId, environmentId: authenticatedEnv.id }, // env-scoped }); ``` Reads are env-scoped; the cancel mutation is not. The same `getDeployment(authenticatedEnv.projectId, …)` helper also backs the deployment *progress* methods (`deployment.server.ts:172,329`), so the projectId-only scope is a small class.

### Runtime PoC (proven on the self-host stack)

Seeded one project with a `prod` env (key `tr_prod_…`) and a `dev` env (key `tr_dev_…`) and one `WorkerDeployment` (`deployment_pocvictim`, status `DEPLOYING`) in the **prod** env. As the **dev** key:

``` status BEFORE : DEPLOYING GET /api/v1/deployments/deployment_pocvictim (dev key) -> 404 (env-scoped read DENIES it) POST /api/v1/deployments/deployment_pocvictim/cancel (dev key) -> 204 status AFTER : CANCELED (prod deploy canceled by the dev key) CONTROL: same cancel with a DIFFERENT project's key -> 404 (projectId scope blocks cross-project) ```

The dev key cannot *read* the prod deployment (404) yet *cancels* it (204 → CANCELED); a different project's key is correctly 404'd — so the gap is precisely cross-environment within a project.