https://www.bleepingcomputer.com/news/security/safari-bug-leaks-your-google-account-info-browsing-history/

There's a problem with the implementation of the IndexedDB API in Safari's WebKit engine, which could result in leaking browsing activity in real-time and even user identities to anyone exploiting this flaw.

IndexedDB is a widely used browser API that is a versatile client-side storage system with no capacity limits.