PHP 8.4 – A Required Update for Continued Security + Stability

Date: 10/02/25
Author: Michael Karfakis, Partner
Contact: mike@vitaminisgood.com | 410-732-6542 x21

Overview
PHP is the scripting language that powers much of the modern web. It drives dynamic functionality — processing logins, powering shopping carts, managing databases, and delivering real-time content updates. In short, PHP is what makes your website work behind the scenes.

Every version of PHP has a defined lifecycle. After that period ends, no further updates — including critical security patches — are released. PHP 8.1 + 8.2 reach the end of security support on December 31, 2025. PHP 8.3 is good for one more year of security updates, but product support ends middle of 2026 so we suggest jumping to 8.4 to avoid another update in a few months. After the 8.4 update, any website still running PHP 8.1 + 8.2 will become increasingly vulnerable to exploits, compatibility failures, and eventual inoperability as hosting environments and dependent services continue to advance.

What Happens If You Don’t Upgrade?
When a PHP version falls out of support:

• Security vulnerabilities remain unpatched. New exploits discovered after December 31, 2025 will not be addressed.
• Extensions and libraries lose compatibility. Vendors stop testing against outdated versions, breaking integrations with payment gateways, shipping APIs, or analytics tools.
• Hosting providers phase out old versions. Your site may eventually stop running altogether once your server environment is updated to maintain compliance.

For these reasons, upgrading to PHP 8.4 before year-end 2025 is not optional — it’s required maintenance to keep your website secure, functional, and supported.

What Changes with PHP 8.4
While PHP 8.4 aims to maintain backward compatibility, several deprecations and behavioral updates may require testing and, in some cases, code or design debugging and repair:

• Implicitly Nullable Parameter Types must be explicitly declared (?User $user = null).
• Dynamic Properties are fully deprecated unless managed through __get()/__set() or the #[AllowDynamicProperties] attribute.
• E_STRICT constant removed, affecting older error-handling logic.
• Extension Unbundling: IMAP, OCI8, PDO_OCI, and pspell now require separate installation via PECL.
• Tighter Type and Error Handling means more TypeErrors in loosely typed or older code.
• MySQLi Deprecations and Exit() Behavioral Change may affect legacy scripts.

These changes reinforce PHP’s evolution toward stronger performance and security but demand careful testing to ensure all site functions continue to perform as expected.

In Summary
Upgrading to PHP 8.4 is not a discretionary improvement — it’s mandatory for operational continuity and data security. Sites remaining on PHP 8.1 beyond December 31, 2025 will be unsupported, exposed to vulnerabilities, and at increasing risk of failure as the web ecosystem moves forward.

Staying current ensures your business remains stable, secure, and serviceable.

Questions? Contact the author. mike@vitaminisgood.com | 410-732-6542 x21