{"id":"CVE-2026-98858","title":"kernel: io_uring: fix task_work add use-after-free with SQPOLL (CVE-2026-98858)","summary":"A flaw was found in the Linux kernel's io_uring subsystem. When submission queue polling (SQPOLL) is enabled, a race condition can cause the polling thread to free the ring context while another operation is still accessing it. A local use…","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-825","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":"2026-10-24T06:18:05+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98858.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98858.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98858"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2555237"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98858"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98858"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98858.mbox"},{"url":"https://git.kernel.org/stable/c/42b3332efacfd2140be4cd0dedad4fb96b8ae90e"},{"url":"https://git.kernel.org/stable/c/891bd8335a0de3bb15c3b797ce3026bbb0dbef6c"},{"url":"https://git.kernel.org/stable/c/395b25968fe854d4efaa19a8e9b7a5b6d1b3eea3"},{"url":"https://git.kernel.org/stable/c/a92193c91e8839fe5fc209616ea95465ae4b919d"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00157,"epssPercentile":0.04763,"ingestedAt":"2026-10-18T16:47:32.461Z","slug":"CVE-2026-98858","body":"## Overview\n\nA flaw was found in the Linux kernel's io_uring subsystem. When submission queue polling (SQPOLL) is enabled, a race condition can cause the polling thread to free the ring context while another operation is still accessing it. A local user can exploit this use-after-free flaw to crash the system, resulting in a Denial of Service (DoS), or potentially achieve privilege escalation.\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-2026-98858.json)\n\n**kernel: io_uring: fix task_work add use-after-free with SQPOLL** — 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":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":228532,"id":"CVE-2026-98858","ts":1792844776125,"field":"cvss","old":null,"new":"5.5"},{"seq":228531,"id":"CVE-2026-98858","ts":1792844776125,"field":"severity","old":"none","new":"medium"}]}