A memory initialization issue was addressed with improved memory handling. This issue is fixed in macOS Big Sur 11.3, iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5. Processing maliciously crafted web content may result in the disclosure of process memory.
CWE-665 - Improper Initialization
The software does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used.