Oct 22, 2026

AI-Found PHP Flaws Push Governments to Take Websites Offline

Two critical PHP flaws, uncovered with help from AI security tools, prompted emergency patches and led governments in Europe and Canada to pull websites offline as attackers began probing for them.

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Governments across Europe and in Canada pulled websites offline on Wednesday after the PHP project shipped emergency fixes for two critical flaws that can let an attacker take over a web server without logging in. The bugs, which reportedly sat in the code for years, were surfaced with the help of AI security tools, and attackers began probing for them within hours of disclosure.

What was fixed

On October 21 the PHP project released versions 8.5.12, 8.4.27, 8.3.36 and 8.2.35 to close CVE-2026-109618 and CVE-2026-109619. Both carry a CVSS v4.0 score of 9.2, and both can lead to unauthenticated remote code execution.

The first flaw involves an out-of-memory condition that can interrupt PHP while internal request data is only partly set up; the cleanup routine may then treat that half-built data as valid. The second involves request-owned internal state that outlives the memory behind it, so a later request handled by the same worker can pick up the stale state before it is reset.

According to the project's advisory, essentially every PHP setup that serves web requests is potentially exposed, including PHP-FPM, Apache with mod_php, php-cgi, FrankenPHP and LiteSpeed. The maintainers single out mod_php as the highest-risk configuration, saying they demonstrated an exploit that fires before any application code runs.

PHP 8.1 and older no longer get official updates. The security team published minimal source backports for PHP 7.4, 8.0 and 8.1, and some Linux distributions and long-term-support vendors are shipping their own patched packages. The project also reminded users that PHP 8.2 reaches end of life on December 31, 2026.

Websites go dark as a precaution

Because PHP sits underneath WordPress, Drupal, Joomla, Magento, shared hosting panels and countless internal tools, the response was swift. Finland temporarily shut down government services and websites. The Register reported that sites belonging to the Dutch parliament, Dutch cybersecurity authorities and the Dutch data protection regulator also went offline, as did the site of privacy group noyb.

Engadget, citing Reuters, said Denmark and France also took at least some government sites down, and that Canada temporarily pulled sites as well. Canada's Minister of Artificial Intelligence and Digital Innovation, Evan Solomon, urged every operator running PHP to update quickly. The BBC and Edinburgh's city council were also reported to have taken pages offline.

CERT-EU issued an advisory ahead of the patches recommending that organizations unable to patch right away isolate internet-facing applications from public networks. In the US, CISA published an alert urging organizations to apply the fixes, and the White House told Reuters it learned of the issue the previous Friday.

The scale worried the open-source community. Tiffany Farriss, interim CEO of the Drupal Association, put it bluntly: "This issue impacts the majority of the Internet."

Exploitation attempts already under way

Security firm watchTowr told The Register it had already observed in-the-wild exploitation attempts using proof-of-concept code with "php2shell" user-agent strings, though it said none had succeeded so far. watchTowr's Jake Knott described the circulating exploits as "vibecoded," a nod to AI-assisted code generation. Huntress, which has dubbed the bugs "PHP2Shell," warned that finding every vulnerable PHP version in an organization can quickly become a sprawling job, since many products never advertise that they run on PHP.

AI on both sides of the disclosure

The episode is one of the clearest examples yet of frontier AI reshaping vulnerability research. In a post published the same day, OpenAI said a researcher credited as Calif found one of the critical flaws using its GPT-5.6 Sol model as part of the company's Patch the Planet initiative. Cloud security firm Wiz independently discovered and reported both bugs. OpenAI said PHP's maintainers led the fix, with Wiz, Cloudflare and others helping with research and coordination over roughly two months.

OpenAI framed the gap between AI-assisted discovery and public disclosure as a "Defender's Window," the time maintainers and security vendors have to build fixes and protections before attackers learn of a flaw. It said it coordinated with the Office of the National Cyber Director, CISA and international partners, released a PHP version checker as a Codex skill on GitHub, and committed $1 billion in subsidized access to its Daybreak security tooling for under-resourced organizations that protect essential services.

The rapid appearance of AI-written exploit code shows how narrow that window can become once details are public.

What site owners should do now

Update immediately to PHP 8.5.12, 8.4.27, 8.3.36 or 8.2.35, or to your distribution's patched package.
If you run PHP 8.1 or older, apply a vendor backport or the project's source backports, and plan an upgrade.
If you cannot patch yet, follow the interim mitigations in PHP's advisory, such as disabling session upload progress, and consider isolating exposed systems. The project stresses these steps reduce risk but do not make a server safe.