The GET /api/v1/stable/durable-tasks/{durable-task} endpoint (listDurableEventLog) is missing tenant authorization validation, allowing any authenticated user to read durable task event logs from any tenant.
The V1 DurableTask stream handler registers worker-supplied durable task external IDs in an in-memory callback routing map before verifying that the authenticated tenant owns the task. If the tenant-scoped ownership check fails, the handler logs the error and continues, but the map entry persists until the stream closes. Durable callback delivery resolves the destination stream by task_external_id only, without checking tenant identity. As a result, a tenant A worker that …
This advisory requires an attacker to successfully guess a durable task's external uuid belonging to another tenant. External ids are generated uuid v4s (uuid.New() in Go), so exploitation requires prior knowledge of a target task UUID through an out-of-band channel. Thus, while the following environments are impacted, there is an extremely low probability it would be exploited.
A cross-tenant write / DoS vulnerability in the Hatchet Dispatcher gRPC service allows any holder of a normal tenant-scoped API token (the lowest credential Hatchet issues — an OWNER of a brand-new tenant) to overwrite the affinity labels of, or disconnect from the dispatcher, any worker UUID belonging to any other tenant on the same Hatchet instance. The two affected RPCs — Dispatcher/UpsertWorkerLabels and Dispatcher/Unsubscribe — read the caller's tenant …
A missing authorization directive on the GET /api/v1/stable/dags/tasks endpoint caused Hatchet's tenant-membership check to be skipped for this route. A user authenticated to any tenant on the same Hatchet instance could query the endpoint with another tenant's UUID and a DAG UUID belonging to that tenant, and receive task metadata for that DAG. This issue has been patched in v0.83.39. Hatchet Cloud has been patched and requires no action from …