{"id":"CVE-2026-89517","title":"kernel: sched_ext: Fix rq->core_pick corruption under core scheduling (CVE-2026-89517)","summary":"A flaw was found in the Linux kernel's `sched_ext` component, which handles core scheduling. When multiple selections on the same core interleave due to a dropped lock, they can corrupt the scheduling state. This corruption can lead to a N…","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-476","vendor":"Red Hat","product":"Red Hat OpenShift Container Platform 4","affected":["openshift_container_platform 4"],"published":"2026-09-11","updated":"2026-09-18","sourceUpdated":"2026-09-18T12:58:35+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89517.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89517.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89517"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532211"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89517"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89517"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89517.mbox"},{"url":"https://git.kernel.org/stable/c/cdafb68155bee2d5c4e50c12e4606323e9334e6b"},{"url":"https://git.kernel.org/stable/c/d954004205c1a1d3f59ce8482b559266c15600fa"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00198,"epssPercentile":0.09806,"ingestedAt":"2026-09-14T11:11:19.887Z","slug":"CVE-2026-89517","body":"## Overview\n\nA flaw was found in the Linux kernel's `sched_ext` component, which handles core scheduling. When multiple selections on the same core interleave due to a dropped lock, they can corrupt the scheduling state. This corruption can lead to a NULL dereference, tasks remaining active after being dequeued, system deadlocks, and ultimately cause the kernel to crash, resulting in a Denial of Service (DoS).\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89517.json)\n\n**kernel: sched_ext: Fix rq->core_pick corruption under core scheduling** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-18.\n\nNot affected:\n\n- Red Hat Enterprise Linux 10\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\nRefer to the advisory for fix availability.","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":204059,"id":"CVE-2026-89517","ts":1789490231238,"field":"cvss","old":null,"new":"5.5"},{"seq":204058,"id":"CVE-2026-89517","ts":1789490231238,"field":"severity","old":"none","new":"medium"},{"seq":147566,"id":"CVE-2026-89517","ts":1789270211411,"field":"cvss","old":null,"new":"5.5"},{"seq":147565,"id":"CVE-2026-89517","ts":1789270211411,"field":"severity","old":"none","new":"medium"},{"seq":109314,"id":"CVE-2026-89517","ts":1789183731391,"field":"cvss","old":null,"new":"5.5"},{"seq":109313,"id":"CVE-2026-89517","ts":1789183731391,"field":"severity","old":"none","new":"medium"}]}