Canonical has released security updates to address critical Linux kernel flaws in Ubuntu systems deployed on Oracle Cloud, Microsoft Azure, and Raspberry Pi devices. These patches target vulnerabilities that could allow attackers to escalate privileges or compromise machines. The updates are available through several Ubuntu Security Notices issued recently.
On October 15, 2025, Canonical announced multiple fixes for serious Linux kernel vulnerabilities affecting Ubuntu variants across various platforms. The security advisories, including USN-7801-3, USN-7810-3, USN-7810-2, USN-7808-2, USN-7821-1, and USN-7791-4, deliver kernel-level patches to prevent remote or local attacks.
For Oracle Cloud, updates in USN-7801-3 and USN-7791-4 target the linux-oracle-6.8 and linux-oracle-6.14 kernels. These patches address issues in dozens of components, such as ARM and x86 architectures, GPU and network drivers, USB controllers, and file systems including Ext4 and SMB. Networking elements like IPv4, IPv6, VLAN, and Netfilter have also been improved for stability and security. Canonical warns that unpatched Oracle systems face risks of privilege escalation or full compromise.
In Microsoft Azure environments, USN-7810-3, USN-7810-2, and USN-7808-2 fix vulnerabilities in the linux-azure-5.15, linux-azure-6.8, and linux-azure-fips kernels. The updates resolve flaws in packet socket handling, network traffic control, and VMware vSockets drivers. They also enhance Ext4 and SMB file systems, TLS protocol handling, and the XFRM subsystem, providing stronger protection for Azure workloads and FIPS-compliant setups.
For Raspberry Pi devices, USN-7821-1 updates the linux-raspi kernel, fixing vulnerabilities in packet sockets, network traffic control, and vSockets. This reduces attack vectors that could lead to elevated privileges on ARM-based systems.
Canonical urges all Ubuntu users, especially system administrators, to apply these kernel updates immediately using standard package management tools. The advisories underscore the ongoing challenges in securing the Linux kernel's complex architecture in multi-cloud and embedded environments.