PHP2Shell Explained: The Real Cause of the PHP RCE Flaws
Category: Cybersecurity News | Vulnerability | Web Security | Published: October 25, 2026 | Reading time: about 12 minutes On October 21, 2026, the PHP project shipped emergency fixes for two critical flaws in the language itself, tracked as CVE-2026-109618 and CVE-2026-109619 and nicknamed PHP2Shell . Both let an unauthenticated visitor run code on a vulnerable server, and both trigger while PHP is still reading an incoming request, before any website code runs. That is why WordPress, Magento, WooCommerce and custom PHP apps were all exposed, even when their own code was clean. Most coverage focused on the panic. This article focuses on the question that matters for defenders: what actually went wrong inside PHP? We cover the root cause of each flaw, how the embargo broke, what attackers did in the first days, and what the fix really changes. We deliberately do not publish exploit details. Key takeaways The root cause is a memory-safety bug class...