Automatically replacing polyfill.io links with Cloudflare’s mirror for a safer Internet

Polyfill.io, a popular JavaScript library service, has been reported to be used for injecting malicious code into users' browsers, posing a threat to the internet due to its widespread use. To mitigate this risk, Cloudflare has released an automatic JavaScript URL rewriting service that replaces any link to polyfill.io with a link to their mirror under cdnjs. This feature is automatically activated for free plan customers and can be turned on with a single click for paid plan customers. It is recommended to remove the use of polyfill.io and replace it with a secure alternative, even if not using Cloudflare.