Readest is a modern, feature-rich ebook reader designed for seamless cross-platform access and an intuitive reading experience. In affected desktop Tauri builds prior to 0.11.10, the apps/readest-app/src-tauri/src/transfer_file.rs commands download_file and upload_file accepted a webview-controlled file_path and passed it to File::create or File::open without checking the Tauri filesystem scope, rejecting absolute paths, or blocking parent-directory traversal. The commands were registered in the global invoke handler for the main, updater, and reader-* windows, so JavaScript executing in the privileged application origin could write attacker-controlled content to any path writable by the process or read and send any path readable by the process. Exploitation requires JavaScript execution in that privileged origin, such as through an application XSS or compromised renderer; whether book-embedded JavaScript can reach the parent origin was not established. The write primitive can overwrite trusted or startup files, while the read primitive can expose keys, tokens, and application secrets. This issue is fixed in version 0.11.10.