{"id":"CVE-2026-89679","title":"kernel: nfsd: fix null dereference in nfsd4_setattr for deleg timestamp attrs (CVE-2026-89679)","summary":"A flaw was found in the Linux kernel's nfsd component. A remote attacker can exploit this by sending a specially crafted SETATTR request that includes specific delegation timestamp attributes and a special NFSv4 state ID. This triggers a n…","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-476","vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","affected":["enterprise_linux 10","enterprise_linux 6"],"published":"2026-09-11","updated":"2026-09-21","sourceUpdated":"2026-09-21T09:50:12+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89679.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89679.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89679"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532085"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89679"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89679"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89679.mbox"},{"url":"https://git.kernel.org/stable/c/3c5119b799a7f57db332b2c31e806de16c869f0f"},{"url":"https://git.kernel.org/stable/c/3c896db123892256fd39af0ee8c2d02c63539983"},{"url":"https://git.kernel.org/stable/c/fe456c8c0931bb3e8a03d429920e87fd85747fba"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00687,"epssPercentile":0.50855,"scores":{"vendor":5.9,"cna":7.5},"ingestedAt":"2026-09-14T15:23:07.473Z","slug":"CVE-2026-89679","body":"## Overview\n\nA flaw was found in the Linux kernel's nfsd component. A remote attacker can exploit this by sending a specially crafted SETATTR request that includes specific delegation timestamp attributes and a special NFSv4 state ID. This triggers a null dereference, leading to a kernel crash and a Denial of Service (DoS). No authentication is required for a successful attack.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10 · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89679.json)\n\n**kernel: nfsd: fix null dereference in nfsd4_setattr for deleg timestamp attrs** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-21.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 6\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 10\n\nNot affected:\n\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\nOut of support scope","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":208492,"id":"CVE-2026-89679","ts":1790005720693,"field":"cvss","old":"5.9","new":"5.5"},{"seq":202984,"id":"CVE-2026-89679","ts":1789403733227,"field":"cvss","old":"7.5","new":"5.9"},{"seq":202983,"id":"CVE-2026-89679","ts":1789403733227,"field":"severity","old":"high","new":"medium"},{"seq":197754,"id":"CVE-2026-89679","ts":1789384318709,"field":"cvss","old":"5.9","new":"7.5"},{"seq":197753,"id":"CVE-2026-89679","ts":1789384318709,"field":"severity","old":"medium","new":"high"},{"seq":183687,"id":"CVE-2026-89679","ts":1789356676951,"field":"cvss","old":"7.5","new":"5.9"},{"seq":183686,"id":"CVE-2026-89679","ts":1789356676951,"field":"severity","old":"high","new":"medium"},{"seq":153550,"id":"CVE-2026-89679","ts":1789285351245,"field":"cvss","old":null,"new":"7.5"},{"seq":153549,"id":"CVE-2026-89679","ts":1789285351245,"field":"severity","old":"none","new":"high"},{"seq":109586,"id":"CVE-2026-89679","ts":1789183732518,"field":"cvss","old":null,"new":"5.9"},{"seq":109585,"id":"CVE-2026-89679","ts":1789183732518,"field":"severity","old":"none","new":"medium"}]}