{"id":"CVE-2026-89694","title":"kernel: nfsd: check client ownership when cancelling a copy-notify stateid (CVE-2026-89694)","summary":"A flaw was found in the Linux kernel's NFSv4.2 server (nfsd). An authenticated NFSv4.2 client could exploit a vulnerability in the `manage_cpntf_state()` function by guessing a state identifier. This improper ownership check allows the cli…","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-639","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":"2026-09-16T12:14:12+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89694.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89694.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89694"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532327"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89694"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89694"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89694.mbox"},{"url":"https://git.kernel.org/stable/c/6bdbfab96e0cf25e5f57dac5c09dc1749751a4bf"},{"url":"https://git.kernel.org/stable/c/b1eca07303594ca27f5dc360a6946bd7e1f5b04c"},{"url":"https://git.kernel.org/stable/c/b42dc26a14b4ad5d6daaada11ec4c70744141c25"},{"url":"https://git.kernel.org/stable/c/d801906165cb5cc250d5cbe44935594e170be3e2"},{"url":"https://git.kernel.org/stable/c/88daaed26e17e1c7e851859b5bbb4f0e1ab6d0e9"},{"url":"https://git.kernel.org/stable/c/81b2cfe767943922eca906a2a5af23a0ce5d0f35"},{"url":"https://git.kernel.org/stable/c/6bba72b8ee68ad631b94bd439592cba46de54d7d"},{"url":"https://git.kernel.org/stable/c/75268f6cfe26b09a7e4d3216367e87fe9e2a26aa"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.0021,"epssPercentile":0.11537,"ingestedAt":"2026-09-14T15:23:07.449Z","slug":"CVE-2026-89694","body":"## Overview\n\nA flaw was found in the Linux kernel's NFSv4.2 server (nfsd). An authenticated NFSv4.2 client could exploit a vulnerability in the `manage_cpntf_state()` function by guessing a state identifier. This improper ownership check allows the client to cancel and free another client's copy-notify stateid, leading to a Denial of Service (DoS) for the legitimate client.\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-2026-89694.json)\n\n**kernel: nfsd: check client ownership when cancelling a copy-notify stateid** — 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\n## Remediation\n\nOut of support scope","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":205449,"id":"CVE-2026-89694","ts":1789576718465,"field":"cvss","old":"5.3","new":"7"},{"seq":205448,"id":"CVE-2026-89694","ts":1789576718465,"field":"severity","old":"medium","new":"high"},{"seq":204011,"id":"CVE-2026-89694","ts":1789490231037,"field":"cvss","old":null,"new":"5.3"},{"seq":204010,"id":"CVE-2026-89694","ts":1789490231037,"field":"severity","old":"none","new":"medium"},{"seq":147369,"id":"CVE-2026-89694","ts":1789270210634,"field":"cvss","old":null,"new":"5.3"},{"seq":147368,"id":"CVE-2026-89694","ts":1789270210634,"field":"severity","old":"none","new":"medium"},{"seq":109124,"id":"CVE-2026-89694","ts":1789183730395,"field":"cvss","old":null,"new":"5.3"},{"seq":109123,"id":"CVE-2026-89694","ts":1789183730395,"field":"severity","old":"none","new":"medium"}]}