This indicates an attack attempt to exploit a Memory Corruption vulnerability in WebKit, a component of Apple Safari.
The vulnerability is due to an error when the vulnerable software attempts to handles a maliciously crafted web page. An attacker may exploit this vulnerability by sending a specially crafted web page.
Apple Computer Safari prior to 12.1.2
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply patches or fixes from the vendor, available from the website: