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🟡 Medium | Source: Microsoft Security Response Center CVE-2025-21888 is a vulnerability in the Linux kernel’s RDMA/mlx5 driver, specifically triggered during the deregistration of a memory region of DM (Device Memory) type, causing an unexpected kernel warning. This flaw affects systems using Mellanox/NVIDIA ConnectX network adapters with RDMA capabilities, which are commonly found in high-performance Azure virtual machine SKUs. While the advisory is sparse on detail, kernel-level RDMA vulnerabilities can affect memory integrity and system stability in workloads relying on high-speed networking. ...

🟡 Medium | Source: Microsoft Security Response Center CVE-2026-23214 is a Linux kernel vulnerability in the btrfs filesystem driver that fails to reject new write transactions when the filesystem is mounted as fully read-only. This could allow unintended write operations to occur in contexts where the filesystem should be strictly protected from modification. For Azure environments, this is relevant to any Linux-based virtual machines or managed services running kernels with the vulnerable btrfs implementation. ...

🟡 Medium | Source: Microsoft Security Response Center CVE-2025-71225 is a Linux kernel vulnerability affecting RAID array management, specifically a race condition that occurs when updating the number of RAID disks via sysfs without first suspending the array. This flaw could lead to system instability or potentially exploitable memory corruption. It is relevant to Azure environments where Linux-based virtual machines or managed services run on kernels with RAID configurations. Security Architect’s Take: Review Linux VM images and Azure Kubernetes Service node pools to ensure host kernels are patched against this vulnerability; prioritise environments using software RAID (md/mdadm) and apply vendor kernel updates promptly via your patching pipeline. ...

🟡 Medium | Source: Microsoft Security Response Center CVE-2026-23213 is a vulnerability in the AMD GPU driver component (drm/amd/pm) affecting the SMU (System Management Unit) Mode 1 reset process, where MMIO (Memory-Mapped I/O) access is not properly disabled during the reset sequence. This flaw could allow unintended memory access during a critical hardware reset phase, potentially leading to information disclosure or system instability. The issue is relevant to Azure workloads running on hardware with AMD GPUs, such as GPU-accelerated virtual machines. ...

🟡 Medium | Source: Microsoft Security Response Center CVE-2025-40213 is a vulnerability in the Linux kernel’s Bluetooth management (MGMT) subsystem, specifically causing a crash in the mesh synchronisation functions. While published via Microsoft’s Security Response Center under Azure, this is a kernel-level flaw that could affect Linux-based virtual machines and containers running in Azure environments. A crash vulnerability of this nature may be exploitable for denial-of-service conditions against affected workloads. Security Architect’s Take: Review whether your Azure Linux VMs or AKS node pools are running kernel versions affected by this Bluetooth MGMT flaw, and apply available kernel patches promptly. Where Bluetooth functionality is unnecessary (common in cloud VMs), consider disabling the Bluetooth kernel module as a hardening measure to reduce attack surface. ...

🟡 Medium | Source: Microsoft Security Response Center CVE-2025-21885 is a vulnerability in the Linux kernel’s RDMA bnxt_re driver, specifically relating to incorrect page details handling for SRQs (Shared Receive Queues) created by kernel consumers. While published via Microsoft’s Security Response Center in the Azure advisory channel, this is a kernel-level flaw affecting RDMA networking components. It matters because RDMA is commonly used in high-performance and HPC workloads on Azure, and kernel memory handling bugs in this area can lead to stability issues or potential privilege escalation. ...

🟡 Medium | Source: Microsoft Security Response Center CVE-2025-21892 is a vulnerability in the Linux kernel’s RDMA/mlx5 driver, specifically affecting the recovery flow of the UMR (User Memory Registration) Queue Pair. This issue is relevant to Azure environments where high-performance networking using Mellanox/NVIDIA ConnectX adapters is in use. A flaw in the error recovery path could potentially lead to instability or exploitation in affected kernel configurations. Security Architect’s Take: Review whether your Azure VMs or HPC workloads use RDMA-capable instance types (such as HB, HC, or ND series); if so, ensure the underlying OS images are patched to a kernel version that includes this fix and monitor Microsoft’s update guidance for any Azure host-level patches. ...

🟡 Medium | Source: Microsoft Security Response Center CVE-2025-40146 is a Linux kernel vulnerability in the block multi-queue (blk-mq) subsystem, where a deadlock condition can occur when the number of requests (nr_requests) is increased. This affects Azure Linux-based virtual machines and container workloads running vulnerable kernel versions. A deadlock in the storage I/O layer can cause system hangs or denial of service, impacting availability of cloud workloads. Security Architect’s Take: Review Azure Linux VM and AKS node pool kernel versions to confirm whether the patched kernel is deployed; prioritise patching or reimaging nodes running affected kernel builds, particularly where storage-intensive or high-throughput workloads are present, as a triggered deadlock could cause full I/O subsystem unavailability. ...

🟡 Medium | Source: Microsoft Security Response Center CVE-2025-21833 is a vulnerability in the Linux kernel’s Intel VT-d IOMMU driver, where a NULL pointer dereference can occur following a WARN_ON_ONCE condition. This affects virtualisation and memory isolation components used in cloud infrastructure. While the Microsoft advisory is currently sparse, IOMMU vulnerabilities can undermine hardware-level isolation between virtual machines, making them significant in multi-tenant cloud environments such as Azure. Security Architect’s Take: Monitor for kernel patch availability for Azure VMs and any underlying host infrastructure you manage. If running Linux workloads on Azure — particularly those relying on hardware virtualisation features — ensure OS-level kernel updates are applied promptly once patches are released, and review whether your workloads are exposed via shared multi-tenant infrastructure. ...

🟡 Medium | Source: Microsoft Security Response Center CVE-2024-58089 is a kernel-level bug in the btrfs filesystem driver that causes a double accounting race condition when a specific memory allocation operation fails. This type of flaw can lead to filesystem corruption or system instability. It affects Linux-based Azure workloads running on kernels that include the btrfs driver. Security Architect’s Take: Review whether any Azure Linux VMs or AKS nodes use btrfs as their filesystem; if so, ensure the underlying OS kernel is patched to the version that includes this fix. Most Azure-managed images default to ext4 or xfs, so exposure may be limited, but custom images warrant explicit verification. ...