PHP 7.2 support patches for Magento 1 are now available. It is critical you are on a supported version of PHP to ensure your site is secure and in compliance. For compatibility and download details, please visit our developer forum post.

https://community.magento.com/t5/News-Announcements/PHP-7-2-Support-Patches-for-Magento-1-are-now-available/m-p/106999#M211