CVE-2026-59226: Open WebUI: Scheduled automations continue after pending-user deactivation and stored model ACL revocation

Open WebUI documents pending as a zero-access role used for new sign-ups and deactivated users, and normal HTTP routes enforce that with get_verified_user() (which rejects pending), while automation create/update/run routes additionally require the features.automations permission. Two paths missed that lifecycle gate, so a deactivated (pending) account could keep acting through the background automation scheduler:

1. Scheduler did not re-gate the owner. When a stored automation became due, execute_automation() rehydrated the owner with Users.get_user_by_id(...) and re-entered the chat completion pipeline without re-checking that the owner was still user/admin or still held features.automations. A still-active automation therefore kept running after its owner was deactivated.
2. Model ACL only enforced for exact role user. check_model_access() applied private-model grants only when user.role == "user", so a pending principal fell through a branch that denies a normal non-owner user.

Net effect: a deactivated account could continue scheduled chat generation through the background worker, consuming the operator’s configured model-provider credentials and reaching a stored automation model ID that its current role/ACL state would no longer permit through normal routes.