Sites Pulled Offline as AI-Aided PHP2Shell Flaw Hits Servers

A pair of critical flaws in PHP, the programming language behind a huge share of the web, was patched on October 21 after details leaked days ahead of schedule. Known as PHP2Shell, the bugs let an attacker run code on a server without logging in. The part that matters for anyone following AI: researchers say AI models helped turn a decades-old weakness into a practical attack.

Two PHP Flaws Allow Remote Code Execution Without a Login

The two bugs, tracked as CVE-2026-109618 and CVE-2026-109619, sit in PHP itself, not in a plugin or a website’s own code, according to Imperva. They involve how PHP handles memory when a request goes wrong. They are believed to affect versions as far back as 5.4, and Help Net Security says every PHP setup that serves web requests is affected. The severity score is 9.2 out of 10.

Researchers Say AI Lowered the Barrier to Exploiting the Bugs

Researchers from Wiz, OpenAI and Calif disclosed the flaws together. Wiz says the underlying problems had been there for decades, but exploiting them took an unusually complex chain of steps, close to the limit of what human researchers could manage. Frontier AI models, it says, made that barrier much lower.

Leaked Details Forced PHP to Release Patches a Day Early

The PHP Foundation planned to release fixes on Thursday. Then news leaked in online forums, and CNBC reports that Calif accidentally posted a proof-of-concept video. The patches came a day early, and the NSA issued its own warning shortly before.

Attackers were already moving. Amazon’s honeypot network recorded an exploit attempt on October 17, four days before the patch, and watchTowr says exploitation is now happening in the wild.

Most PHP Installations Are Internet-Facing, and Many Won’t Get a Fix

Qualys looked at data from 12,000 customers and found about 166 million PHP installations, 74% of them internet-facing. Around 70% of those with a known version run branches that no longer get official support, so they won’t receive a fix.

Supported versions can be patched by updating to PHP 8.5.12, 8.4.27, 8.3.36 or 8.2.35. watchTowr notes that PHP says no configuration change fully closes the flaws. Cloudflare also turned on firewall protection by default for its customers from October 21 as a stopgap.

AI Is Shrinking the Gap Between Discovery and Attack

The pattern is the real story. A flaw that sat unnoticed for years was found and weaponized quickly with AI help, and attackers had a head start before most defenders knew it existed. If that gap keeps shrinking, patching speed will matter more than ever.