{"id":"CVE-2026-98593","title":"kernel: s390/debug: Fix NULL pointer dereference in debug_info_copy() (CVE-2026-98593)","summary":"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…","severity":"medium","cvss":4.1,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":"CWE-476","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 6","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-10-18","updated":"2026-10-20","sourceUpdated":"2026-10-20T04:52:19+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98593.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98593.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98593"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2555038"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98593"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98593"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98593.mbox"},{"url":"https://git.kernel.org/stable/c/13decd3b3b3a4d8a2e603fb8c9ffde0c6be3c225"},{"url":"https://git.kernel.org/stable/c/a19bede30f0da5ae56782edac62b5998a7434cba"},{"url":"https://git.kernel.org/stable/c/33f706884821da9cb55b650b7b1d4f2bdf800137"},{"url":"https://git.kernel.org/stable/c/2de9c458cc49d8db6408a7c5fbf0c7c94fe4d52b"},{"url":"https://git.kernel.org/stable/c/9c6af88fbefbe77608b77409df23a1617e28398c"},{"url":"https://git.kernel.org/stable/c/c593f38e1cdb92f87d01be4c4e5ac12417b1454b"},{"url":"https://git.kernel.org/stable/c/012bfcd5a51082d5a65f096dfb9ca652b5267965"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00173,"epssPercentile":0.06622,"ingestedAt":"2026-10-18T15:45:12.248Z","slug":"CVE-2026-98593","body":"## Overview\n\nA 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.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-20 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98593.json)\n\n**kernel: s390/debug: Fix NULL pointer dereference in debug_info_copy()** — rated Moderate by Red Hat. Released 2026-10-18, updated 2026-10-20.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\nNot affected:\n\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\n## Remediation\n\nOut of support scope","depth":"sunlit","depthScore":23,"depthScoreParts":{"impact":22.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":225718,"id":"CVE-2026-98593","ts":1792498384433,"field":"cvss","old":null,"new":"4.1"},{"seq":225717,"id":"CVE-2026-98593","ts":1792498384433,"field":"severity","old":"none","new":"medium"}]}