{"id":"CVE-2026-98440","title":"kernel: KVM: arm64: nv: Delay freeing of shadow S2 structures until VM destruction (CVE-2026-98440)","summary":"A flaw was found in the Linux kernel's Kernel-based Virtual Machine (KVM) subsystem on ARM64 architectures. In nested virtualization configurations, shadow memory management structures are prematurely freed during shadow page flushes while…","severity":"medium","cvss":5.6,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H","cvssSource":"vendor","cwe":"CWE-826","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-10-18","updated":"2026-10-24","sourceUpdated":"2026-10-24T14:23:02+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98440.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98440.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98440"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2554866"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98440"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98440"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98440.mbox"},{"url":"https://git.kernel.org/stable/c/876049f026b4dfaca0cc78ec81be0e639ca8525d"},{"url":"https://git.kernel.org/stable/c/22e82acec93a681071ed36f70eabe2d0c4e0bebd"},{"url":"https://git.kernel.org/stable/c/5bf1c9175e657b3c2dc1cf77403031ac7aadcf66"},{"url":"https://git.kernel.org/stable/c/e5843f4effaa2ffac3e789ecd4456403564961d4"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00122,"epssPercentile":0.01931,"scores":{"vendor":5.6,"cna":7},"ingestedAt":"2026-10-18T15:45:12.307Z","slug":"CVE-2026-98440","body":"## Overview\n\nA flaw was found in the Linux kernel's Kernel-based Virtual Machine (KVM) subsystem on ARM64 architectures. In nested virtualization configurations, shadow memory management structures are prematurely freed during shadow page flushes while other parts of the system may still reference them. A local user with permissions to run virtual machines can exploit this flaw to trigger a use-after-free condition, resulting in a denial of service (DoS) via a system crash or potential memory corruption.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98440.json)\n\n**kernel: KVM: arm64: nv: Delay freeing of shadow S2 structures until VM destruction** — rated Moderate by Red Hat. Released 2026-10-18, updated 2026-10-24.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\nNo fix planned:\n\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 6\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\nFix deferred","depth":"sunlit","depthScore":31,"depthScoreParts":{"impact":30.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":229551,"id":"CVE-2026-98440","ts":1793019841471,"field":"cvss","old":"7","new":"5.6"},{"seq":229550,"id":"CVE-2026-98440","ts":1793019841471,"field":"severity","old":"high","new":"medium"},{"seq":228984,"id":"CVE-2026-98440","ts":1792854130447,"field":"cvss","old":null,"new":"7"},{"seq":228983,"id":"CVE-2026-98440","ts":1792854130447,"field":"severity","old":"none","new":"high"}]}