Researchers have discovered a critical vulnerability, named “Sinkclose,” in AMD processors that has existed for nearly 18 years. This flaw allows attackers to deeply embed malicious code in the processor’s firmware, making it extremely difficult to detect or remove—even after a system format. The vulnerability affects nearly all AMD processors since 2006, and despite AMD’s efforts to patch some products, the issue remains largely unresolved. Security experts are concerned about the potential for state-sponsored exploitation of this flaw.