CVE-2026-89459

A flaw was found in the Linux kernel's s390/percpu component. This vulnerability arises when the kernel is compiled with older versions of GNU as (prior to binutils 2.39). A parsing error prevents a crucial instruction from being correctly processed, which can lead to issues with system resource management after a process migrates between CPUs. This can result in system instability and potentially a Denial of Service (DoS).

This flaw is rated as Moderate severity because exploitation requires local access, is restricted strictly to the IBM zSystems (s390x) architecture, and can result in kernel instability or denial of service without compromising confidentiality or integrity. The issue only manifests in kernels built for s390 using older assembler versions where a per-CPU address repair instruction was omitted during assembly. Standard enterprise workloads on other CPU architectures are entirely unaffected.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.