Vulnerability in the Linux Kernel's VXLAN Component Affects Data Handling

CVE-2026-80838

What is CVE-2026-80838?

A vulnerability exists in the Linux kernel's VXLAN component, where a bulk flush operation can inadvertently unlink the last remote entry in the Forwarding Database (FDB). This breach in protocol occurs when a filtered flush attempts to clear entries, leading to potential manipulation of data and invalid memory access. Specifically, an RCU reader may reference an empty list head after the last remote is unlinked, enabling a scenario where the receive learning path can mistakenly read from and write to incorrect memory locations. To mitigate this issue, the proper functioning of the FDB must be ensured, so that the last remote remains linked during operations, ensuring data integrity and preventing unauthorized access.

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