Critical PHP Security Update in October 2026: What WordPress Website Owners Need to Do

If you run a WordPress website, you should check your PHP version as soon as possible. On October 21, 2026, the PHP project released security updates to fix two critical vulnerabilities that could allow attackers to execute malicious code on vulnerable servers without authentication.

This security issue is not limited to WordPress. It can affect any server running a vulnerable version of PHP, including websites built with other PHP applications.

The official WordPress team has advised website owners to update PHP immediately.

Source: WordPress – Critical PHP Security Release

What Is the PHP Security Issue?

PHP is a server-side programming language used by WordPress to process website requests, communicate with databases, and generate web pages.

On October 21, 2026, the PHP project released security updates addressing two critical vulnerabilities:

• CVE-2026-109618: A vulnerability related to memory handling when PHP encounters an out-of-memory condition.
• CVE-2026-109619: A vulnerability involving outdated internal state and memory that has already been released.

Under certain conditions, these vulnerabilities could allow an unauthenticated attacker to execute code on a vulnerable server. This is known as remote code execution, or RCE.

Successful exploitation could put the website and its server at risk. However, this does not mean every website running PHP has been compromised.

Source: Official PHP Security Release Information

Which PHP Versions Should You Update?

The PHP project has released security fixes for the following versions:

If your website runs one of these PHP branches, check whether your hosting provider has installed the corresponding security update or a newer patched release.

PHP versions older than 8.2 no longer receive security updates from the PHP project. Websites running these older versions should be treated as a priority because they need an upgrade to a supported PHP version, not simply a routine update.

PHP 8.2 is also approaching the end of its security support period on December 31, 2026. Website owners should plan to move to a newer supported version.

Source: PHP Official News Archive

How to Check Your WordPress PHP Version

You can check your website’s PHP version directly from the WordPress dashboard.

Follow these steps:

1. Log in to your WordPress admin dashboard.
2. Go to Tools → Site Health.
3. Open the Info tab.
4. Expand the Server section.
5. Find the PHP version information.

You can also check your PHP version through your web hosting control panel. The exact location depends on your hosting provider.

Remember that checking the version is only the first step. You also need to confirm that the installed version includes the security fixes.

How to Protect Your WordPress Website

Here are the actions I recommend taking as soon as possible.

1. Contact Your Hosting Provider

If you use managed WordPress hosting, your hosting provider may already be working on the update. However, do not assume that your website is protected without checking.

Contact your hosting provider and ask whether the PHP security patches released on October 21, 2026, have been applied to your server.

If you manage your own server, arrange to install the appropriate security update immediately.

2. Update PHP to a Patched Version

If your server is running a vulnerable PHP version, upgrade it to a patched release or a newer supported version.

Before changing PHP versions, check whether your WordPress theme, plugins, and custom code are compatible with the target version.

For business websites and WooCommerce stores, test the upgrade on a staging site whenever possible. This helps identify compatibility problems before they affect your live website.

If you cannot apply the security fixes immediately, seek urgent assistance from your hosting provider. Official cybersecurity guidance recommends considering taking exposed systems offline until they can be adequately protected.

3. Back Up Your Website

Before making significant server changes, create a complete backup of your website, including:

• WordPress files and uploaded media.
• The WordPress database.
• Your current server and PHP configuration, where applicable.

A backup gives you a recovery option if the PHP upgrade causes compatibility issues. However, a backup does not protect a vulnerable website by itself.

4. Check Your WordPress Themes and Plugins

Although this security issue originates in PHP rather than WordPress itself, your website still needs regular maintenance.

Update WordPress, themes, and plugins when security or maintenance releases are available. Review outdated plugins and themes, especially those that are no longer maintained.

Also, test important website functions after the PHP upgrade, including contact forms, login pages, payment processing, checkout, and other business-critical features.

5. Do Not Rely on a Firewall Alone

A web application firewall (WAF) may help reduce exposure to certain attacks. Your hosting provider may also deploy additional mitigation rules.

However, these measures should not replace installing the official PHP security updates. Follow the guidance from PHP and your hosting provider to confirm that the server is properly protected.

Does WordPress Need a Separate Security Update?

According to the official WordPress announcement, no separate WordPress update is required or planned for these PHP vulnerabilities.

The problem exists in PHP itself, so the primary action is to update the PHP environment that runs your website.

Updating WordPress alone will not fix a vulnerable PHP installation.

This is an important distinction for website owners who regularly check the WordPress dashboard for updates but do not monitor their server’s PHP version.

Source: WordPress Security Announcement

My Recommendation for WordPress Website Owners

As a WordPress website owner, you should treat PHP security updates as part of your regular website maintenance routine.

I recommend the following priorities:

1. Check the PHP version on every website you manage.
2. Confirm with your hosting provider that the latest applicable security patches have been installed.
3. Upgrade unsupported PHP versions to a supported release.
4. Test your website after changing PHP versions.
5. Keep regular backups and monitor important website functions.

If you manage multiple WordPress websites for clients, include PHP version checks in your maintenance checklist. This is particularly important for WooCommerce stores and business websites that handle customer information or online payments.

Conclusion

The October 2026 PHP security release addresses two critical vulnerabilities that could allow attackers to execute malicious code on vulnerable servers.

The good news is that security fixes are available. The important step is to ensure your hosting environment is updated rather than assuming that WordPress updates or security plugins will solve the problem.

Check your PHP version today, confirm that the security patches have been applied, and plan an upgrade if your website uses an unsupported PHP version.

Official References

• WordPress: Critical PHP Security Release
• PHP: Official Security Releases and News
• UK National Cyber Security Centre: Critical Security Issue Affecting PHP