This indicates an attack attempt to exploit an Out Of Bounds Memory Access vulnerability in Oracle Java SE.
The vulnerability is due to an error in the application when handling a maliciously crafted web page which includes a Java applet file. A remote attacker may be able exploit this to execute arbitrary code within the context of the application or possibly cause a denial of service condition.
Oracle Java SE 5.0u81 and prior
Oracle Java SE 6u91 and prior
Oracle Java SE 7u76 and prior
Oracle Java SE 8u40 and prior
System Compromise: Remote attackers can gain control of the vulnerable systems.
Denial of Service: Remote attackers can crash vulnerable systems.
Apply the most recent upgrade or patch from the vendor.