{"id":"CVE-2026-98865","title":"kernel: sched_ext: Don't run ops.dequeue() with a DSQ lock held (CVE-2026-98865)","summary":"A flaw was found in the Linux kernel's sched_ext subsystem. A local attacker could cause a Denial of Service (DoS) by triggering a deadlock condition when running an extensible scheduler program that accesses a dispatch queue while a lock …","severity":"medium","cvss":4.4,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":"CWE-833","vendor":"Red Hat","product":"Linux","affected":["Linux >= ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d < fe499ae9da46e297f578d4346c4c8e338c3118db","Linux >= ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d < cb86607ada73185f321baa7f9d94a08a3a40bbf5","Linux 7.1"],"published":"2026-10-18","updated":"2026-10-24","sourceUpdated":"2026-10-24T06:56:16+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98865.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98865.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98865"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2555245"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98865"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98865"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98865.mbox"},{"url":"https://git.kernel.org/stable/c/fe499ae9da46e297f578d4346c4c8e338c3118db"},{"url":"https://git.kernel.org/stable/c/cb86607ada73185f321baa7f9d94a08a3a40bbf5"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00169,"epssPercentile":0.06179,"ingestedAt":"2026-10-18T16:47:32.460Z","slug":"CVE-2026-98865","body":"## Overview\n\nA flaw was found in the Linux kernel's sched_ext subsystem. A local attacker could cause a Denial of Service (DoS) by triggering a deadlock condition when running an extensible scheduler program that accesses a dispatch queue while a lock is held during task dequeue operations. This issue causes the scheduler to hang, rendering the system unresponsive.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · updated 2026-10-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98865.json)\n\n**kernel: sched_ext: Don't run ops.dequeue() with a DSQ lock held** — rated Moderate by Red Hat. Released 2026-10-18, updated 2026-10-24.\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":24,"depthScoreParts":{"impact":24.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":228522,"id":"CVE-2026-98865","ts":1792844773519,"field":"cvss","old":null,"new":"4.4"},{"seq":228521,"id":"CVE-2026-98865","ts":1792844773519,"field":"severity","old":"none","new":"medium"}]}