MPLS Payload Length Validation Vulnerability in Linux Kernel by Open vSwitch

CVE-2026-31679

What is CVE-2026-31679?

A vulnerability in the Linux kernel affecting Open vSwitch allows for improper validation of MPLS payload lengths in SET and SET_MASKED actions. The validate_set() function mistakenly accepts variable-sized MPLS payloads, which can lead to unexpected behaviors during action handling. The kernel expects fixed-size MPLS key data, and failure to validate this can compromise network integrity. To address this issue, the kernel has been updated to reject non-matching MPLS action key sizes early, enhancing operational security and mitigating potential exploits.

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