USN-8668-2: Linux kernel (Raspberry Pi) vulnerabilities
Several security vulnerabilities affecting the Linux kernel used in Raspberry Pi systems have been identified. These issues include improper validation in the NTFS file system that can expose sensitive kernel memory, and hardware-related bugs in AMD processors that may leak sensitive information or allow privilege escalation. Additional vulnerabilities span many subsystems of the Linux kernel, potentially allowing attackers to compromise the system. Users are advised to update their systems to patched Linux kernel versions to mitigate these risks.
Published 21/9/2026, 1:04:55 pmVerified 21/9/2026, 1:59:43 pmRevision 1
In plain language
What this advisory means
Several security vulnerabilities affecting the Linux kernel used in Raspberry Pi systems have been identified. These issues include improper validation in the NTFS file system that can expose sensitive kernel memory, and hardware-related bugs in AMD processors that may leak sensitive information or allow privilege escalation. Additional vulnerabilities span many subsystems of the Linux kernel, potentially allowing attackers to compromise the system. Users are advised to update their systems to patched Linux kernel versions to mitigate these risks.
Technical explanation
How the issue affects the environment
The Linux kernel's NTFS file system implementation failed to properly validate file name length under certain conditions, leading to an out-of-bounds read and possible exposure of kernel memory (CVE-2023-45896). Some AMD processors had flaws in speculative execution where the floating point divider unit did not clear data correctly, allowing local attackers to observe sensitive information (CVE-2025-54505). Further, AMD Zen 2 processors did not adequately isolate shared resources in the operation cache, potentially permitting local attackers to corrupt instructions at higher privilege levels, resulting in privilege escalation (CVE-2025-54518). Numerous other vulnerabilities affect various architectures (ARM32, ARM64, MIPS, PowerPC, S390, x86) and kernel subsystems such as drivers, cryptographic APIs, filesystems, networking, and security modules. These collectively increase risks of system compromise. The vulnerabilities were addressed by updates to relevant Linux kernel packages for Raspberry Pi systems.
Operational impact
Why teams should care
If exploited, these vulnerabilities could lead to unauthorized disclosure of sensitive information, privilege escalation, or complete system compromise on devices running affected versions of the Linux kernel, notably Raspberry Pi systems. This poses risks to the confidentiality, integrity, and availability of systems and data. Organizations relying on these systems should prioritize applying updates to reduce potential operational and security risks.
Immediate action
Update the Linux kernel on Raspberry Pi systems to version 5.15.0-1106.109 or later by performing a standard system update and then rebooting the system. Due to ABI changes, recompilation and reinstallation of all third-party kernel modules are required to maintain compatibility.
Affected and fixed releases
Affected versionsLinux kernel for Raspberry Pi prior to 5.15.0-1106.109
Fixed versionsLinux kernel for Raspberry Pi version 5.15.0-1106.109 and later
Temporary risk reduction
The official source does not specify any workaround measures; applying the recommended kernel updates is the primary remediation approach.
Evidence and validation checklist
Ubuntu Security Notice USN-8668-2 published on 21 September 2026
Details about CVE-2023-45896, CVE-2025-54505, CVE-2025-54518 vulnerabilities
List of affected Linux kernel subsystems and architectures
Update instructions including required package versions and note on module recompilation
Authoritative reference
Ubuntu Security Notices
QCS detected and normalized this record from the official source. Vendor guidance remains authoritative.
