Four new security vulnerabilities affecting Intel microprocessor have been publicly disclosed earlier, and Intel already released updated microcode firmware to mitigate them, but in the case of Linux-based operating system these flaws cannot be addressed only by updating the CPU firmware, but also by installing new Linux kernel versions and QEMU patches. The vulnerabilities (CVE-2018-12126, CVE-2018-12127, CVE-2018-12130, and CVE-2019-11091) affect various Intel processors and could allow a local attacker to expose sensitive information. They have an impact on all supported Ubuntu Linux releases, including Ubuntu 19.04 (Disco Dingo), Ubuntu 18.10 (Cosmic Cuttlefish), Ubuntu 18.04 LTS (Bionic Beaver), Ubuntu 16.04 LTS (Xenial Xerus), and Ubuntu 14.04 ESM (Trusty Tahr).