{"id":"CVE-2026-89697","title":"kernel: nfsd: add fh_want_write() for early-verified SETATTR in nfsd_proc_setattr() (CVE-2026-89697)","summary":"A flaw was found in the Linux kernel's Network File System Daemon (nfsd). When setting file attributes using `nfsd_proc_setattr()`, a specific code path (`BOTH_TIME_SET` branch) prematurely verifies file handles. This bypasses a critical w…","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-911","vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","affected":["enterprise_linux 6","enterprise_linux 7","enterprise_linux 8","openshift_container_platform 4"],"published":"2026-09-11","updated":"2026-09-15","sourceUpdated":"2026-09-15T19:50:18+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89697.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89697.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89697"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532144"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89697"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89697"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89697.mbox"},{"url":"https://git.kernel.org/stable/c/3eec9d791968c177a4a8cda9af5c04f79dae09cb"},{"url":"https://git.kernel.org/stable/c/9229d824b938f4fb0ea7a5dddade51735e6fe6f9"},{"url":"https://git.kernel.org/stable/c/2150305134889fb2fc25228d35353bd2f6f29500"},{"url":"https://git.kernel.org/stable/c/d823bf9285cdf4514873b85ab5a888878dd4e8f4"},{"url":"https://git.kernel.org/stable/c/15ca3b64a69caa6194bed8f98a20ed90a11c11dd"},{"url":"https://git.kernel.org/stable/c/533964d420d385e11b08dd4c56c66ef5dcccaf08"},{"url":"https://git.kernel.org/stable/c/c4a409b86a92815181a8e9395c6bf1696ad19175"},{"url":"https://git.kernel.org/stable/c/4e475be769aa9f7a2c1ce55a2b8592cfccacddcc"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00686,"epssPercentile":0.50815,"scores":{"vendor":7,"cna":9.1},"ingestedAt":"2026-09-14T15:23:07.449Z","slug":"CVE-2026-89697","body":"## Overview\n\nA flaw was found in the Linux kernel's Network File System Daemon (nfsd). When setting file attributes using `nfsd_proc_setattr()`, a specific code path (`BOTH_TIME_SET` branch) prematurely verifies file handles. This bypasses a critical write verification step (`fh_want_write()`), allowing file attribute changes to proceed without a proper mount write reference. This could lead to unauthorized modification of file metadata or content, potentially impacting data integrity.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat OpenShift Container Platform 4 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89697.json)\n\n**kernel: nfsd: add fh_want_write() for early-verified SETATTR in nfsd_proc_setattr()** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-15.\n\nAffected:\n\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n- Red Hat OpenShift Container Platform 4\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n- Red Hat OpenShift Container Platform 4\n\nNot affected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 9\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":205524,"id":"CVE-2026-89697","ts":1789576723322,"field":"cvss","old":"9.1","new":"7"},{"seq":205523,"id":"CVE-2026-89697","ts":1789576723322,"field":"severity","old":"critical","new":"high"},{"seq":197726,"id":"CVE-2026-89697","ts":1789384318575,"field":"cvss","old":"6.8","new":"9.1"},{"seq":197725,"id":"CVE-2026-89697","ts":1789384318575,"field":"severity","old":"medium","new":"critical"},{"seq":183673,"id":"CVE-2026-89697","ts":1789356676889,"field":"cvss","old":"9.1","new":"6.8"},{"seq":183672,"id":"CVE-2026-89697","ts":1789356676889,"field":"severity","old":"critical","new":"medium"},{"seq":153580,"id":"CVE-2026-89697","ts":1789285351363,"field":"cvss","old":null,"new":"9.1"},{"seq":153579,"id":"CVE-2026-89697","ts":1789285351363,"field":"severity","old":"none","new":"critical"},{"seq":147768,"id":"CVE-2026-89697","ts":1789270212214,"field":"cvss","old":null,"new":"6.8"},{"seq":147767,"id":"CVE-2026-89697","ts":1789270212214,"field":"severity","old":"none","new":"medium"},{"seq":109506,"id":"CVE-2026-89697","ts":1789183732196,"field":"cvss","old":null,"new":"6.8"},{"seq":109505,"id":"CVE-2026-89697","ts":1789183732196,"field":"severity","old":"none","new":"medium"}]}