CVE-2024-26664 is a vulnerability identified in the Linux kernel's hardware monitoring (hwmon) subsystem, specifically within the coretemp driver responsible for monitoring CPU temperature sensors. The flaw arises from an out-of-bounds memory access due to improper ordering of operations: the pdata->cpu_map[] array is assigned before the code performs a boundary check on the index. This bug can be triggered on systems with more than 128 cores per CPU package, which leads to an index exceeding the allocated array bounds. Such out-of-bounds access can cause undefined behavior including memory corruption, potential kernel crashes (denial of service), or possibly privilege escalation if exploited carefully. The vulnerability affects multiple Linux kernel versions as indicated by the commit hashes, and it was publicly disclosed on April 2, 2024. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet. The issue is technical and specific to high-core-count CPU systems, which are increasingly common in enterprise and data center environments. The fix involves reordering the code logic to ensure the boundary check occurs before any array assignment, preventing out-of-bounds access.

For European organizations, especially those operating large-scale data centers, cloud infrastructure, or high-performance computing environments utilizing Linux servers with CPUs having more than 128 cores per package, this vulnerability poses a risk of system instability or denial of service due to kernel crashes. While no active exploitation is reported, the potential for memory corruption could be leveraged by attackers to escalate privileges or execute arbitrary code within the kernel context, compromising confidentiality, integrity, and availability of critical systems. This is particularly relevant for sectors such as finance, telecommunications, research institutions, and government agencies that rely heavily on Linux-based infrastructure. The disruption caused by kernel panics or forced reboots could lead to operational downtime, data loss, or service interruptions. Additionally, the complexity of the vulnerability means that only skilled attackers with local access or the ability to run code on the affected system could exploit it, somewhat limiting the attack surface but not eliminating risk.

European organizations should prioritize updating their Linux kernel to the patched versions that address CVE-2024-26664 as soon as possible, especially on systems with CPUs exceeding 128 cores per package. System administrators should audit their hardware inventory to identify affected machines and apply kernel updates promptly. Additionally, implementing strict access controls to limit local user privileges can reduce the risk of exploitation since the vulnerability requires code execution on the host. Employing kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR), and enabling security modules like SELinux or AppArmor can provide additional layers of defense. Monitoring system logs for kernel warnings or crashes related to hwmon or coretemp drivers can help detect potential exploitation attempts. For environments where immediate patching is not feasible, consider isolating vulnerable systems or restricting user access to mitigate risk. Finally, maintain up-to-date backups and incident response plans to minimize impact in case of exploitation.