CVE-2026-98593

A flaw was found in the Linux kernel's s390 debug subsystem. This vulnerability allows a local user to cause a Denial of Service (DoS) through a kernel crash. When static debug registration encounters an error, internal memory pointers are cleared while boundary records remain active. A local user attempting to read or copy the affected debug area, such as by opening its view file, triggers a NULL pointer dereference (an invalid memory access) that crashes the kernel.

This vulnerability is rated as Moderate severity because exploiting it requires privileged local access to kernel debug interfaces, is limited to the IBM Z (s390x) platform, and results solely in a system crash without compromising confidentiality or integrity. Triggering the condition additionally relies on a preceding initialization failure within the s390 diagnostic logging facility. Environments deployed on non-s390x architectures are not impacted.

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.