This XSS payload utilizes the replace method in JavaScript to bypass WAF protection. The payload inserts a malicious alert function within the context, which can execute arbitrary JavaScript code. This bypass technique is inspired by the 'JavaScript for Hackers' book by @garethheyes. It is important for WAF vendors to be aware of such evasion techniques to enhance their security measures.
For more details, check out the original tweet here: https://twitter.com/thelilnix/status/1912185244997787998