{"id":"CVE-2026-89706","title":"kernel: nfsd: Reset write verifier when async COPY writeback fails (CVE-2026-89706)","summary":"A flaw was found in the Linux kernel's nfsd component. When an asynchronous (async) copy writeback operation fails, the server's write verifier is not properly reset. This can lead to a client incorrectly assuming that data has been made d…","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-367","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":"2026-09-16T05:50:14+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89706.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89706.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89706"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532347"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89706"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89706"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89706.mbox"},{"url":"https://git.kernel.org/stable/c/cc5f7cef0659a27c13dd33edd8e2f79257b095c6"},{"url":"https://git.kernel.org/stable/c/c6d2f6372c7e0f76b9c148ff7696aec64da0b5b7"},{"url":"https://git.kernel.org/stable/c/8a08ffe73eb2aa6bc6f88763da7e2b55bab6493a"},{"url":"https://git.kernel.org/stable/c/6b13d26cc21b6320a3c61d5e4cee2ce9a589b181"},{"url":"https://git.kernel.org/stable/c/31d4d0a62ec4bafbcdbad142f11ab1f90794b1d0"},{"url":"https://git.kernel.org/stable/c/591134e059e3456180244a826d6917cdc183140b"},{"url":"https://git.kernel.org/stable/c/bf0cd31a9abcb728c17d79b4c2cc533612a8b6af"},{"url":"https://git.kernel.org/stable/c/f5cb2276954cb80987a93ef9f9dfbfdbfc0f10b9"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00511,"epssPercentile":0.42643,"scores":{"vendor":7,"cna":7.5},"ingestedAt":"2026-09-14T15:23:07.449Z","slug":"CVE-2026-89706","body":"## Overview\n\nA flaw was found in the Linux kernel's nfsd component. When an asynchronous (async) copy writeback operation fails, the server's write verifier is not properly reset. This can lead to a client incorrectly assuming that data has been made durable, resulting in the silent loss of data that was intended to be copied.\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-2026-89706.json)\n\n**kernel: nfsd: Reset write verifier when async COPY writeback fails** — 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":205494,"id":"CVE-2026-89706","ts":1789576721994,"field":"cvss","old":"7.5","new":"7"},{"seq":197716,"id":"CVE-2026-89706","ts":1789384318525,"field":"cvss","old":"6.8","new":"7.5"},{"seq":197715,"id":"CVE-2026-89706","ts":1789384318525,"field":"severity","old":"medium","new":"high"},{"seq":183663,"id":"CVE-2026-89706","ts":1789356676836,"field":"cvss","old":"7.5","new":"6.8"},{"seq":183662,"id":"CVE-2026-89706","ts":1789356676836,"field":"severity","old":"high","new":"medium"},{"seq":153592,"id":"CVE-2026-89706","ts":1789285351412,"field":"cvss","old":null,"new":"7.5"},{"seq":153591,"id":"CVE-2026-89706","ts":1789285351412,"field":"severity","old":"none","new":"high"},{"seq":147337,"id":"CVE-2026-89706","ts":1789270210511,"field":"cvss","old":null,"new":"6.8"},{"seq":147336,"id":"CVE-2026-89706","ts":1789270210511,"field":"severity","old":"none","new":"medium"},{"seq":109092,"id":"CVE-2026-89706","ts":1789183730274,"field":"cvss","old":null,"new":"6.8"},{"seq":109091,"id":"CVE-2026-89706","ts":1789183730274,"field":"severity","old":"none","new":"medium"}]}