What are the implications of maintaining a project with known security risks, such as using an old CMS or PHP version?

Maintaining a project with known security risks, such as using an old CMS or PHP version, can leave the project vulnerable to cyber attacks and data breaches. To mitigate these risks, it is essential to regularly update the CMS and PHP version to the latest stable release, which includes security patches and fixes for known vulnerabilities.

```php
// Example code snippet to update PHP version to the latest stable release
// This code should be run on the server where PHP is installed

sudo apt-get update
sudo apt-get install php
```

Remember to always backup your project before making any major updates to ensure you can revert back in case of any issues.