An issue was found in redundant REX instruction prefix values affecting third generation Intel Xeon Scalable (“Icelake“) processors. The issue may allow a local third-party actor using such instructions to cause a denial of service (DOS) or achieve privilege escalation. CVE-2023-23583 only affects Amazon Linux customers on EC2 metal platforms. Please refer to the AWS Security Bulletin for more information on the affected instance families and the impacts on AWS services: (https://aws.amazon.com/security/security-bulletins/AWS-2023-013)