{"id":"CVE-2026-89688","title":"kernel: nfsd: drop the stateid, not the stateowner, on seqid_op replay retry (CVE-2026-89688)","summary":"A flaw was found in the Linux kernel's nfsd component. During a `seqid_op` replay retry, the system incorrectly handles reference counts for stateowners, leading to a reference count underflow and a use-after-free vulnerability. This issue…","severity":"high","cvss":7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"vendor","cwe":"CWE-825","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 6","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-09-11","updated":"2026-09-16","sourceUpdated":"2026-09-16T04:38:12+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89688.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89688.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89688"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532337"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89688"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89688"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89688.mbox"},{"url":"https://git.kernel.org/stable/c/00843074d9b84824552c9679d423d29500ca5de0"},{"url":"https://git.kernel.org/stable/c/5e4627d3513e60accfce9d5f4c7fa95251ef93d6"},{"url":"https://git.kernel.org/stable/c/69ed78b6b947c9257213164678b4edf17533093b"},{"url":"https://git.kernel.org/stable/c/f7cb90ddc021747fc9abfd4cf5252d425fd34eec"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00608,"epssPercentile":0.47777,"scores":{"vendor":5.3,"cna":9.8},"ingestedAt":"2026-09-14T15:23:07.473Z","slug":"CVE-2026-89688","body":"## Overview\n\nA flaw was found in the Linux kernel's nfsd component. During a `seqid_op` replay retry, the system incorrectly handles reference counts for stateowners, leading to a reference count underflow and a use-after-free vulnerability. This issue could allow an attacker to potentially cause a denial of service or execute arbitrary code.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89688.json)\n\n**kernel: nfsd: drop the stateid, not the stateowner, on seqid_op replay retry** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-16.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 6\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 7\n- Red Hat Enterprise Linux 8\n- Red Hat OpenShift Container Platform 4\n\n## Remediation\n\nOut of support scope","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":205502,"id":"CVE-2026-89688","ts":1789576722319,"field":"cvss","old":"5.3","new":"7"},{"seq":205501,"id":"CVE-2026-89688","ts":1789576722319,"field":"severity","old":"medium","new":"high"},{"seq":202982,"id":"CVE-2026-89688","ts":1789403733219,"field":"cvss","old":"9.8","new":"5.3"},{"seq":202981,"id":"CVE-2026-89688","ts":1789403733219,"field":"severity","old":"critical","new":"medium"},{"seq":197736,"id":"CVE-2026-89688","ts":1789384318625,"field":"cvss","old":"5.3","new":"9.8"},{"seq":197735,"id":"CVE-2026-89688","ts":1789384318625,"field":"severity","old":"medium","new":"critical"},{"seq":183681,"id":"CVE-2026-89688","ts":1789356676925,"field":"cvss","old":"9.8","new":"5.3"},{"seq":183680,"id":"CVE-2026-89688","ts":1789356676925,"field":"severity","old":"critical","new":"medium"},{"seq":153566,"id":"CVE-2026-89688","ts":1789285351309,"field":"cvss","old":null,"new":"9.8"},{"seq":153565,"id":"CVE-2026-89688","ts":1789285351309,"field":"severity","old":"none","new":"critical"},{"seq":147361,"id":"CVE-2026-89688","ts":1789270210604,"field":"cvss","old":null,"new":"5.3"},{"seq":147360,"id":"CVE-2026-89688","ts":1789270210604,"field":"severity","old":"none","new":"medium"},{"seq":109112,"id":"CVE-2026-89688","ts":1789183730349,"field":"cvss","old":null,"new":"5.3"},{"seq":109111,"id":"CVE-2026-89688","ts":1789183730349,"field":"severity","old":"none","new":"medium"}]}