Critical Linux Kernel Vulnerabilities Affect AMD Zen Processors

Severity: High (Score: 72.0)

Sources: Ubuntu

Summary

On April 16, 2026, Ubuntu published updates regarding critical vulnerabilities in the Linux kernel, specifically affecting AMD Zen processors. The flaw, known as EntrySign (CVE-2024-36347), allows privileged attackers to load malicious CPU microcode, potentially compromising system integrity and confidentiality. Multiple subsystems within the Linux kernel are impacted, including MIPS, PowerPC, and x86 architectures, as well as various drivers and file systems. The vulnerabilities could allow attackers to exploit these weaknesses to gain unauthorized access to systems. The updates aim to address these security issues and mitigate potential attacks. Security professionals are urged to apply the patches immediately to protect affected systems. The vulnerabilities were discovered by researchers Josh Eads, Kristoffer Janke, Eduardo Vela Nava, Tavis Ormandy, and Matteo Rizzo. The CVE for this vulnerability was published on June 27, 2025. Key Points: • EntrySign vulnerability (CVE-2024-36347) allows malicious CPU microcode loading. • Affected subsystems include MIPS, PowerPC, x86 architectures, and various drivers. • Immediate patching is recommended to mitigate potential exploitation risks.

Key Entities

• Malware (attack_type)
• CVE-2024-36347 (cve)
• Linux (platform)
• Linux kernel (platform)
• EntrySign (vulnerability)