Vulnerability in Linux Kernel Affecting x86 Architecture

CVE-2026-99186

What is CVE-2026-99186?

This vulnerability arises from a flaw in the Linux kernel's handling of x86 segment registers. An improper shadowing of loop counters during instruction prefix evaluation can lead to a denial of service condition. Specifically, when a user executes certain instructions with a segment prefix, the kernel may become unresponsive, hogging CPU resources indefinitely, until a system reboot is required. This can result in significant disruption to services relying on the kernel and demands prompt action for resolution.

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