Multiple security vulnerabilities were discovered in the Linux kernel for AWS systems, including a flaw known as VMSCAPE that involves insufficient branch predictor isolation between a guest VM and a userspace hypervisor on certain processors. This flaw could allow an attacker in a guest VM to potentially expose sensitive information from the host OS. Additional issues affect the HSI, Bluetooth, and Timer subsystems. These vulnerabilities could be used by an attacker to compromise the system. A security update addressing these issues is available and requires a system reboot and recompilation of third-party kernel modules due to an ABI change.