This issue was addressed through improved state management. This issue is fixed in tvOS 18.4, Safari 18.4, iPadOS 17.7.6, iOS 18.4 and iPadOS 18.4, macOS Sequoia 15.4. A malicious website may be able to track users in Safari private browsing mode.
https://support.apple.com/en-us/122379
https://support.apple.com/en-us/122377
https://support.apple.com/en-us/122373