This indicates an attack attempt to exploit a Sandbox Bypass vulnerability in Microsoft Internet Explorer.
The vulnerability is due to an error when the vulnerable software attempts to handles maliciously crafted web page. An attacker can exploit this by tricking a user into visiting a malicious webpage and escape sandbox mode within the context of the process.
Internet Explorer 10
Internet Explorer 11
Internet Explorer 11 on Windows 10
Security Bypass: Remote attackers can bypass security mechanism on vulnerable systems
Apply the most recent upgrade or patch from the vendor