The set of vulnerabilities is dubbed PHP2Shell and disclosure is scheduled for 14:00 UTC with attacks expected to follow soon after.
It is adviced to take offline every non-vital services until the patch has been installed (or the Docker image has been updated with a patched version of PHP)
Update: fix is out https://www.php.net/archive/2026.php#2026-10-21-5


They didn’t move fast enough on it and others began circulating it. So they had to play catch up, hence the need to react before they had a patch.
https://thephp.foundation/blog/2026/10/21/todays-php-security-release-and-how-were-strengthening-php-security/