A total of 27 bugs were squashed with the release of macOS Catalina 10.15.4, affecting components such as Bluetooth, Call History, CoreFoundation, FaceTime, Kernel, libxml2, Mail, sudo, and Time Machine, among others.

The patched flaws could result in the execution of arbitrary code with system or kernel privileges, leak of kernel memory, privilege escalation, leak of sensitive information, disclosure of restricted memory, or code signing bypass.