What are the security implications of running multiple PHP versions on the same server and how can they be mitigated?

Running multiple PHP versions on the same server can introduce security vulnerabilities due to outdated or unsupported versions of PHP being used. To mitigate this, it is recommended to isolate each PHP version in its own environment using containers or virtualization. This way, any vulnerabilities in one version will not affect the others.

// Example of isolating PHP versions using Docker containers

// Dockerfile for PHP version 7.4
FROM php:7.4
COPY . /var/www/html
CMD ["php", "-S", "0.0.0.0:80"]

// Dockerfile for PHP version 8.0
FROM php:8.0
COPY . /var/www/html
CMD ["php", "-S", "0.0.0.0:80"]