[USN-7939-1] Linux kernel (Azure) vulnerabilities
== Ubuntu Security Notice USN-7939-1 December 16, 2025 linux-azure, linux-azure-5.4 vulnerabilities == A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 20.04 LTS - Ubuntu 18.04 LTS Summary: Several security issues were fixed in the Linux kernel. Software Description: - linux-azure: Linux kernel for Microsoft Azure Cloud systems - linux-azure-5.4: Linux kernel for Microsoft Azure cloud systems Details: Jean-Claude Graf, Sandro Rüegge, Ali Hajiabadi, and Kaveh Razavi discovered that the Linux kernel contained insufficient branch predictor isolation between a guest and a userspace hypervisor for certain processors. This flaw is known as VMSCAPE. An attacker in a guest VM could possibly use this to expose sensitive information from the host OS. (CVE-2025-40300) Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - Cryptographic API; - ACPI drivers; - HSI subsystem; - I3C subsystem; - InfiniBand drivers; - Media drivers; - Network drivers; - Pin controllers subsystem; - AFS file system; - F2FS file system; - SMB network file system; - Padata parallel execution mechanism; - Timer subsystem; - Tracing infrastructure; - Memory management; - Appletalk network protocol; - Networking core; - Netfilter; (CVE-2022-49026, CVE-2022-49390, CVE-2023-52854, CVE-2024-35867, CVE-2024-47691, CVE-2024-49935, CVE-2024-50061, CVE-2024-50067, CVE-2024-50095, CVE-2024-50196, CVE-2024-53090, CVE-2024-53218, CVE-2024-56664, CVE-2025-21727, CVE-2025-21855, CVE-2025-37838, CVE-2025-37958, CVE-2025-38352, CVE-2025-38666, CVE-2025-39964, CVE-2025-39993, CVE-2025-40018) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 20.04 LTS linux-image-5.4.0-1156-azure5.4.0-1156.163 Available with Ubuntu Pro linux-image-azure-5.4 5.4.0.1156.150 Available with Ubuntu Pro linux-image-azure-lts-20.04 5.4.0.1156.150 Available with Ubuntu Pro Ubuntu 18.04 LTS linux-image-5.4.0-1156-azure5.4.0-1156.163~18.04.1 Available with Ubuntu Pro linux-image-azure 5.4.0.1156.163~18.04.1 Available with Ubuntu Pro linux-image-azure-5.4 5.4.0.1156.163~18.04.1 Available with Ubuntu Pro After a standard system update you need to reboot your computer to make all the necessary changes. ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well. References: https://ubuntu.com/security/notices/USN-7939-1 CVE-2022-49026, CVE-2022-49390, CVE-2023-52854, CVE-2024-35867, CVE-2024-47691, CVE-2024-49935, CVE-2024-50061, CVE-2024-50067, CVE-2024-50095, CVE-2024-50196, CVE-2024-53090, CVE-2024-53218, CVE-2024-56664, CVE-2025-21727, CVE-2025-21855, CVE-2025-37838, CVE-2025-37958, CVE-2025-38352, CVE-2025-38666, CVE-2025-39964, CVE-2025-39993, CVE-2025-40018, CVE-2025-40300 OpenPGP_signature.asc Description: OpenPGP digital signature
[USN-7939-1] Linux kernel (Azure) vulnerabilities
== Ubuntu Security Notice USN-7939-1 December 16, 2025 linux-azure, linux-azure-5.4 vulnerabilities == A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 20.04 LTS - Ubuntu 18.04 LTS Summary: Several security issues were fixed in the Linux kernel. Software Description: - linux-azure: Linux kernel for Microsoft Azure Cloud systems - linux-azure-5.4: Linux kernel for Microsoft Azure cloud systems Details: Jean-Claude Graf, Sandro Rüegge, Ali Hajiabadi, and Kaveh Razavi discovered that the Linux kernel contained insufficient branch predictor isolation between a guest and a userspace hypervisor for certain processors. This flaw is known as VMSCAPE. An attacker in a guest VM could possibly use this to expose sensitive information from the host OS. (CVE-2025-40300) Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - Cryptographic API; - ACPI drivers; - HSI subsystem; - I3C subsystem; - InfiniBand drivers; - Media drivers; - Network drivers; - Pin controllers subsystem; - AFS file system; - F2FS file system; - SMB network file system; - Padata parallel execution mechanism; - Timer subsystem; - Tracing infrastructure; - Memory management; - Appletalk network protocol; - Networking core; - Netfilter; (CVE-2022-49026, CVE-2022-49390, CVE-2023-52854, CVE-2024-35867, CVE-2024-47691, CVE-2024-49935, CVE-2024-50061, CVE-2024-50067, CVE-2024-50095, CVE-2024-50196, CVE-2024-53090, CVE-2024-53218, CVE-2024-56664, CVE-2025-21727, CVE-2025-21855, CVE-2025-37838, CVE-2025-37958, CVE-2025-38352, CVE-2025-38666, CVE-2025-39964, CVE-2025-39993, CVE-2025-40018) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 20.04 LTS linux-image-5.4.0-1156-azure5.4.0-1156.163 Available with Ubuntu Pro linux-image-azure-5.4 5.4.0.1156.150 Available with Ubuntu Pro linux-image-azure-lts-20.04 5.4.0.1156.150 Available with Ubuntu Pro Ubuntu 18.04 LTS linux-image-5.4.0-1156-azure5.4.0-1156.163~18.04.1 Available with Ubuntu Pro linux-image-azure 5.4.0.1156.163~18.04.1 Available with Ubuntu Pro linux-image-azure-5.4 5.4.0.1156.163~18.04.1 Available with Ubuntu Pro After a standard system update you need to reboot your computer to make all the necessary changes. ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well. References: https://ubuntu.com/security/notices/USN-7939-1 CVE-2022-49026, CVE-2022-49390, CVE-2023-52854, CVE-2024-35867, CVE-2024-47691, CVE-2024-49935, CVE-2024-50061, CVE-2024-50067, CVE-2024-50095, CVE-2024-50196, CVE-2024-53090, CVE-2024-53218, CVE-2024-56664, CVE-2025-21727, CVE-2025-21855, CVE-2025-37838, CVE-2025-37958, CVE-2025-38352, CVE-2025-38666, CVE-2025-39964, CVE-2025-39993, CVE-2025-40018, CVE-2025-40300 OpenPGP_signature.asc Description: OpenPGP digital signature
