OpenAI ships a Codex skill to check sites for PHP2Shell

If you run PHP sites, upgrade to PHP 8.5.12, 8.4.27, 8.3.36 or 8.2.35, the patched releases CISA lists. To see which sites still show an old version, point Codex at the checker skill OpenAI published today.

What changed#

PHP shipped those releases around 9:30 AM ET Oct 21 for CVE-2026-109618 and CVE-2026-109619, per Huntress. CISA says the flaws "allow for unauthenticated remote code execution in PHP and affect all PHP installations serving web requests." OpenAI says Calif found one of them with GPT-5.6 Sol through its Patch the Planet program, and Wiz found and reported both on its own.

At 12:35 PM ET, @OpenAI posted that it "packaged a Codex skill to help check." The repo has two skills: phpcheck-url when you only have a URL, phpcheck-server when you can log in.

Why it matters#

Our read: the check runs in a coding agent many teams already use, so a first pass over your sites is one prompt. OpenAI says it expects similar findings "to increase sharply in the coming months."

How to use it#

These steps follow OpenAI's README and skill files.

1. Ask Codex to install both skills:

$skill-installer install both skills from https://github.com/openai/php2shell-checker

2. With only a URL, run $phpcheck-url check https://example.com.
3. With server access, run $phpcheck-server check the PHP version serving my site. The server skill says to confirm php -v matches the PHP your web server runs.
4. Read the result. The README warns: "UNKNOWN does not mean the target is patched!"
5. Upgrade, or as Huntress relays from PHP: "Check with your vendor for updated PHP packages."

Good to know#

• Headers only. The URL check reads X-Powered-By and Server. The README warns "distribution backports may not change the upstream version," so a patched server can look old; the URL skill calls a server-side check "stronger evidence."
• PHP 8.1 and older. Huntress says they "won't receive official updates," though PHP posted minimal source backports for 7.4 to 8.1. Huntress's stopgap is session.upload_progress.enabled = Off, but OpenAI's server skill cautions "Configuration settings alone do not establish that PHP is patched." CISA says to take such systems offline until patched.
• The timelines differ by source. OpenAI says "frontier AI found these vulnerabilities before attackers did." Huntress says details "leaked online before their coordinated disclosure and before patches were released" on Oct 20; it saw no exploitation as of 10 AM ET Oct 21, but "others are reporting that they are seeing attacks emerging." CISA says it "has not observed exploitation of these vulnerabilities as of the time of publication."
• Watch next: Huntress says it will update its post with indicators and detection guidance; a change to CISA's exploitation line is the other signal.