MultiVendorX WordPress plugin: vendors can read other stores' private data

MultiVendorX plugin for WordPress before 5.0.22 contains a broken access control vulnerability in the /wp-json/multivendorx/v1/stores REST route that allows authenticated vendors to access administrative flag handlers due to the store_owner role possessing the edit_stores capability and missing per-store ownership checks. Attackers can exploit the insecure direct object reference in the visitorMap handler and other flag handlers to retrieve other stores' contact emails, pending withdrawal amounts, onboarding and registration data, deactivation reasons, and visitor analytics, resulting in a cross-tenant confidentiality breach.