🟡 Medium | Source: Microsoft Security Response Center
CVE-2026-64590 is a Linux kernel vulnerability in the dma-buf/udmabuf subsystem, relating to redundant CPU cache synchronisation that triggers an EEXIST warning on cacheline operations. This is a kernel-level flaw that could affect Linux-based Azure virtual machines and containerised workloads relying on shared memory buffer mechanisms. Microsoft has published information on this CVE as part of their update guidance.
Security Architect’s Take: Review whether your Azure Linux VMs or AKS node pools are running kernel versions affected by this dma-buf issue, and prioritise kernel patching cycles accordingly. Where possible, enable automatic OS image updates on node pools and VM scale sets to reduce exposure windows.
Original advisory: CVE-2026-64590 dma-buf/udmabuf: skip redundant cpu sync to fix cacheline EEXIST warning