Google has changed how a core component of the Chrome browser works in order to add additional privacy protections for its users. From a report:
[…] With Chrome 86, released earlier this week, Google has rolled out important changes to this mechanism. Known as “cache partitioning,” this feature works by changing how resources are saved in the HTTP cache based on two additional factors. From now on, a resource’s storage key will contain three items, instead of one: The top-level site domain (http://a.example), the resource’s current frame (http://c.example), and the resource’s URL (https://x.example/doge.png). By adding additional keys to the cache pre-load checking process, Chrome has effectively blocked all the past attacks against its cache mechanism, as most website components will only have access to their own resources and won’t be able to check resources they have not created themselves.