Grav API Plugin (Composer package getgrav/grav-plugin-api) before 1.0.10 fails to properly validate the slug field in the POST /pages/{route}/move endpoint. PagesController::move() sanitizes the slug only with ltrim($body['slug'], '.'), which strips leading periods but does not neutralize '/' or '..' segments. An authenticated API caller with the api.pages.write permission can supply path traversal sequences (e.g., 01.home/../../../pwned) to move an entire page directory (content and media) to an arbitrary writable location outside user/pages/, including outside the Grav installation.