The issue was addressed with improved memory handling. This issue is fixed in Safari 18.6, macOS Sequoia 15.6, iPadOS 17.7.9, iOS 18.6 and iPadOS 18.6, tvOS 18.6, watchOS 11.6, visionOS 2.6. Processing web content may lead to a denial-of-service.
https://support.apple.com/en-us/124155
https://support.apple.com/en-us/124154
https://support.apple.com/en-us/124153
https://support.apple.com/en-us/124152
https://support.apple.com/en-us/124149