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Critical

Critical remote code execution vulnerabilities in PHP require immediate updates

PHP released security updates to fix vulnerabilities that allow remote code execution, so developers using affected versions should update their environments immediately.

Advisory date21 Oct 2026
SeverityCritical
ReferenceCVE-2026-109618, CVE-2026-109619
AffectedPHP 8.2 to 8.5 and all versions 8.1 or older
Fixed in8.2.35, 8.3.36, 8.4.27, 8.5.12

What happened

PHP released several updates to address memory corruption and state management issues which could allow an attacker to run code on your server. These vulnerabilities affect how the engine handles memory during specific operations; consequently, an attacker could take control of the host. Security researchers have already observed attempts to exploit them in the wild, although some reports remain unconfirmed.

Who is affected

You are at risk if you run PHP versions 8.2 through 8.5, because the underlying flaws exist in the core engine. Anyone running PHP 8.1 or older remains unprotected because those versions no longer receive security patches. Check your specific distribution for backported fixes.

Why it matters if you build with AI

AI tools often generate or interact with PHP code that runs on your infrastructure, which means a vulnerability in the runtime can compromise your entire application. Ensuring your environment is secure allows you to deploy AI-generated features without introducing known paths for remote attacks. Keeping the underlying engine updated is a fundamental step in maintaining a secure AI implementation.

What to do

  • Update PHP to the latest patched version for your branch.
  • Verify the running version because some distributions backport fixes without changing version numbers.
  • Migrate applications still running on PHP 8.1 or older to a supported version.
  • Confirm your production environment uses the new binaries.

Locaas is being built to track advisories like this, check your running applications and propose the necessary updates for your approval.

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