WordPress is one of the most widely used website platforms, but that also makes it a favorite target for hackers. Among all security issues, cross-site scripting (XSS) is the most common, accounting for 53.3% of all new WordPress vulnerabilities.

How Does XSS Work?

XSS is an attack where a hacker injects malicious JavaScript into a website. When visitors load the page, the script executes in their browser, which can lead to:

• Stolen cookies and session data.
• Redirects to phishing sites.
• Manipulated page content.
• Hidden login forms that steal credentials.

How Do Hackers Inject XSS into WordPress?

1. Vulnerable Forms on the Site

If your website has comment sections, contact forms, or review fields that don’t properly sanitize inputs, a hacker can insert a malicious script.

✅ Example Attack:

<script>alert('Your site is hacked!');</script>

If the site doesn’t filter this input, the script executes in visitors’ browsers.

2. Abandoned Plugins and Themes

In 2023, the number of abandoned plugins and themes skyrocketed—from 147 in 2022 to 827 in 2023. Even worse, the number of removed vulnerable plugins jumped from 87 in 2022 to 481 in 2023.

Security firm Patchstack issued a warning:

“We reported 404 of these plugins at once to draw attention to the ‘zombie plugin pandemic’ in WordPress. These plugins seem modern and safe at first, but often contain unpatched security holes. Worse yet, they can remain active on websites even after being removed from the WordPress plugin repository.”

3. Bad Data Handling in Plugins

Some plugins take user input and display it on a page without proper sanitization, opening the door for XSS.

✅ Example of Poor Security:

echo "<h1>Hello, " . $_GET['name'] . "!</h1>";

A hacker can modify the URL like this:

https://example.com/?name=<script>alert('XSS')</script>

Now, anyone who visits this link will trigger the malicious JavaScript.

How to Protect Your WordPress Site from XSS

✅ Sanitize User Input
Use esc_html(), esc_attr(), and esc_js() to clean up user input:

echo esc_html($_GET['name']);

✅ Allow Only Specific HTML Tags with wp_kses()

echo wp_kses($_POST['comment'], ['b' => [], 'i' => []]);

✅ Set a Content Security Policy (CSP)
Modify your .htaccess file:

Header set Content-Security-Policy "default-src 'self'; script-src 'self';"

✅ Keep Plugins and Themes Updated
Hackers target outdated software, so regular updates are crucial.

✅ Disable HTML in Comments

add_filter('pre_comment_content', 'wp_strip_all_tags');

Conclusion

Cross-site scripting (XSS) is the biggest security issue in WordPress, actively used by hackers to attack websites. Most attacks happen through unprotected input fields, outdated plugins, and poor data handling.

The best way to stay secure? Use WordPress’s built-in security features, sanitize all user inputs, and keep your plugins/themes updated. The more proactive you are about security, the harder it is for hackers to break in! 🚀