Linux Kernel Vulnerability Affecting Segmentation Routing Paths

CVE-2026-31668

What is CVE-2026-31668?

The Linux kernel's segmentation lightweight tunnel (seg6 lwtunnel) vulnerability introduces routing inconsistencies due to the use of a unified destination cache for input and output paths. This design flaw allows different routing contexts to exhaustively share a single cache, leading to context mismatches and potential security exposures. The proposed fix involves creating separate caches for input and output processes to ensure independent management and prevent unintended data exposure during segmentation routing. This correction enhances the kernel's robustness against manipulation and maintains the integrity of network operations.

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