Guide to checking the security and speed of WordPress sites: How to protect your site from XML-RPC vulnerabilities and achieve record speed in 2026?

Why are WordPress sites exposed to constant hacking attempts and consuming resources?

Due to the global popularity of the WordPress system, it is considered the most targeted environment by botnets and automated guessing attacks (Brute Force Attacks). In most cases, hacking does not occur due to a flaw in the WordPress core itself, but rather due to vulnerabilities in nulled themes, out of date plugins, or ports open by default without the knowledge of the site owner.

In this practical guide, we reveal the most important technical measures that every company must implement to secure and speed up its site on the server.

1. Close the dangerous XML-RPC port (Block XML-RPC Attacks)

The xmlrpc.php file is an older protocol that allows external connection to WordPress. Today, botnet malware exploits it to perform thousands of password guessing attempts in a single HTTP request (Amplified Brute Force), causing the server to crash and exceed processor and memory consumption.

You can immediately check if the XML-RPC port is open on your site using our free tool WordPress and Security Checker and close it via the .htaccess file or through the Nginx/LiteSpeed server settings.

2. Prevent usernames from being leaked via the REST API

In a default WordPress installation, any visitor can access /wp-json/wp/v2/users to extract a complete list of site administrators and article authors. Knowing the username cuts the hacker halfway through guessing. Public access to this path should be restricted to non-registered users.

3. Impact of heavy commercial templates on site slowdown and Core Web Vitals

A lot of companies use pre-made templates stuffed with hundreds of additional CSS and JS files and slow page builders. This results in a higher initial TTFB response time and a lower Google site rating. The ideal solution is to rely on lightweight custom templates built with Gutenberg Blocks or a modern framework such as TailwindCSS.

4. Instant site scanning with MTM4WEB smart tools

In order to empower business owners and developers, we have provided a free live inspection tools package without any registration:

• WP Health Checker: Detects XML-RPC file security, user leaks and active version.
• WordPress theme and plugin detector: Reveals the name of the theme and plugins used on any competing site.
• A tool for measuring the speed of websites and servers: It measures the time of TTFB, DNS, and data transfer scheme in milliseconds.
• Comprehensive SEO Check Tool: Checks internal SEO standards and mobile compatibility in a documented technical report.