CVE-2026-48037: @hulumi/baseline: AccountFoundation reuse paths silently downgrade GuardDuty / Security Hub posture

AccountFoundation can either create AWS detective services (GuardDuty for threat detection, Security Hub for compliance dashboards) or reuse pre-existing ones via opt-in flags. The reuse paths just imported the existing resources and reported success — they never checked whether the existing services were actually doing their job.

1. GuardDuty reuse. If the existing detector was suspended, or set to the slower 6-hour publishing cadence instead of the baseline 15-minute one, or otherwise misconfigured — Hulumi never noticed. The deployment succeeded with a misleadingly-positive guardDutyDetectorId output as if the baseline were active.
2. Security Hub reuse. Although the account import was read-only, Hulumi unconditionally created the CIS / NIST StandardsSubscription resources with default delete behaviour. Pulumi then treated those subscriptions as its own — a later pulumi destroy of the stack would call BatchDisableStandards, unsubscribing the account from CIS / NIST compliance monitoring even on accounts that had those subscriptions before Hulumi ever ran.