{"id":"CVE-2026-89520","title":"kernel: sched/core: Make core-sched flips wait for in-flight selections (CVE-2026-89520)","summary":"A flaw was found in the Linux kernel's core scheduling component. A race condition can occur when core scheduling flips complete during task selection, leading to incorrect lock handling. This can result in a resource leak and system insta…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":"CWE-366","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-09-11","updated":"2026-09-18","sourceUpdated":"2026-09-18T13:04:45+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89520.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89520.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89520"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532271"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89520"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89520"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89520.mbox"},{"url":"https://git.kernel.org/stable/c/23eda24f325a6e6d686d30ec75f2e9d6745e2015"},{"url":"https://git.kernel.org/stable/c/9d69422ddaa13526c2223444e237d948d6e44728"},{"url":"https://git.kernel.org/stable/c/f3629c63a4af3e491381780bc6c123cb498c4c40"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00161,"epssPercentile":0.05759,"scores":{"vendor":4.7,"cna":7.8},"ingestedAt":"2026-09-14T15:23:07.475Z","slug":"CVE-2026-89520","body":"## Overview\n\nA flaw was found in the Linux kernel's core scheduling component. A race condition can occur when core scheduling flips complete during task selection, leading to incorrect lock handling. This can result in a resource leak and system instability, potentially causing a denial of service.\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 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89520.json)\n\n**kernel: sched/core: Make core-sched flips wait for in-flight selections** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-18.\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 OpenShift Container Platform 4\n\n## Remediation\n\nFix deferred","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":206931,"id":"CVE-2026-89520","ts":1789749705172,"field":"cvss","old":"4.7","new":"5.5"},{"seq":202895,"id":"CVE-2026-89520","ts":1789403732846,"field":"cvss","old":"7.8","new":"4.7"},{"seq":202894,"id":"CVE-2026-89520","ts":1789403732846,"field":"severity","old":"high","new":"medium"},{"seq":197981,"id":"CVE-2026-89520","ts":1789384321240,"field":"cvss","old":"4.7","new":"7.8"},{"seq":197980,"id":"CVE-2026-89520","ts":1789384321240,"field":"severity","old":"medium","new":"high"},{"seq":183500,"id":"CVE-2026-89520","ts":1789356675624,"field":"cvss","old":"7.8","new":"4.7"},{"seq":183499,"id":"CVE-2026-89520","ts":1789356675624,"field":"severity","old":"high","new":"medium"},{"seq":153308,"id":"CVE-2026-89520","ts":1789285349982,"field":"cvss","old":null,"new":"7.8"},{"seq":153307,"id":"CVE-2026-89520","ts":1789285349982,"field":"severity","old":"none","new":"high"},{"seq":147454,"id":"CVE-2026-89520","ts":1789270210971,"field":"cvss","old":null,"new":"4.7"},{"seq":147453,"id":"CVE-2026-89520","ts":1789270210971,"field":"severity","old":"none","new":"medium"},{"seq":109214,"id":"CVE-2026-89520","ts":1789183730756,"field":"cvss","old":null,"new":"4.7"},{"seq":109213,"id":"CVE-2026-89520","ts":1789183730756,"field":"severity","old":"none","new":"medium"}]}