heym before 0.0.105 Authentication Bypass via Redis Node

heym before 0.0.105 does not act on the result of the credential authorization lookup in the Redis workflow node (backend/app/services/node_execution/nodes/redis_node.py). When _get_accessible_credential returns None — because the credential ID does not exist or the caller is not authorized to use it — the node treats the lookup failure as an empty configuration and falls back to defaults, connecting to localhost:6379 with no password and executing the requested operation there. The same fallback occurs when an accessible credential has an empty config or no redis_host value. An authenticated workflow author who supplies a credential ID they do not own, or one that was deleted, therefore obtains a read/write connection to whatever Redis is listening on the backend's loopback interface instead of an error. Impact depends on the deployment: the stock docker-compose.yml ships no Redis, in which case the flaw surfaces as a misleading connection error rather than data exposure.