Umbraco Delivery API allows for cached requests to be returned with an invalid API key
Umbraco's content delivery API can be restricted from public access such that an API key must be provided in a header to authorize the request. It's also possible to configure output caching, such that the delivery API outputs will be cached for a period of time, improving performance. There's an issue when these two things are used together though in that the caching doesn't vary by the header that contains …