What happened
Published 2026-09-26 (unrated): a three-issue authorization cluster in the MCP Server for WordPress plugin — nonce bypass enabling admin-only actions, insufficient capability checks on workflow CRUD, and missing object-level check on a workflow route disclosing post metadata.
Why it matters
This plugin is a bridge between WordPress sites and external LLM agents (MCP); broken authz lets unauthenticated or low-privilege attackers reconfigure the site's agent workflows or take admin actions through the MCP tool surface.
Attack vector
Cookie-authenticated REST requests can bypass nonce verification under a condition an attacker influences, enabling unauthenticated administrator-only actions; separate missing capability/object-level checks let Contributors alter site-wide AI-agent workflow configuration and enumerate other users' private content.
Affected systems
MCP Server for WordPress plugin before 1.8.2 (REST workflow routes).
Mitigation
Upgrade to MCP Server for WordPress 1.8.2 (WPScan advisories d8e97a77-b70f-41f0-8d1e-0d50b6d878c6, f814fb88-4198-4ba0-972c-658a1d672289, 79c3ae87-fc63-42b1-bb68-c7420060f9d4).