{"id":"CVE-2026-89699","title":"kernel: nfsd: validate symlink target length in NFSv4 CREATE (CVE-2026-89699)","summary":"A flaw was found in the Linux kernel's Network File System Daemon (nfsd) when handling NFSv4 CREATE operations. A remote attacker can exploit this by sending a crafted request with an oversized symbolic link (symlink) target length. This u…","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-770","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 6","enterprise_linux 7","enterprise_linux 8","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-09-11","updated":"2026-09-21","sourceUpdated":"2026-09-21T12:26:02+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89699.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89699.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89699"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532157"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89699"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89699"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89699.mbox"},{"url":"https://git.kernel.org/stable/c/36011308b3f01ce7dc9954f3cefcbb5291af9f95"},{"url":"https://git.kernel.org/stable/c/888dad4b557352cf85be31613407b5ba51ad07d1"},{"url":"https://git.kernel.org/stable/c/8661d3cb38fd148947e57dbc0871fd4d3fa33bbf"},{"url":"https://git.kernel.org/stable/c/3ef5e7a01a4d74995a65496bc9166d1e980a4355"},{"url":"https://git.kernel.org/stable/c/b24843ea3de1676b29902457b38507c95a80649b"},{"url":"https://git.kernel.org/stable/c/895a485cd3758031ef9993c0d53cf19ce8fb4ccc"},{"url":"https://git.kernel.org/stable/c/45ec115cbfecb4b3cfab7fca6f73d1b60696a25a"},{"url":"https://git.kernel.org/stable/c/041f57056e5fb9c80adc088269322d2c61074406"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00508,"epssPercentile":0.42222,"scores":{"vendor":5.5,"cna":7.5},"ingestedAt":"2026-09-14T15:23:07.449Z","slug":"CVE-2026-89699","body":"## Overview\n\nA flaw was found in the Linux kernel's Network File System Daemon (nfsd) when handling NFSv4 CREATE operations. A remote attacker can exploit this by sending a crafted request with an oversized symbolic link (symlink) target length. This unbounded length can force the kernel to allocate a large amount of memory, leading to a denial of service (DoS) condition on the system.\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 7, Red Hat Enterprise Linux 8, 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 7, Red Hat Enterprise Linux 8, … · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89699.json)\n\n**kernel: nfsd: validate symlink target length in NFSv4 CREATE** — 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- 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\nNo fix planned:\n\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 10\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":208457,"id":"CVE-2026-89699","ts":1790005706244,"field":"cvss","old":"7.5","new":"5.5"},{"seq":208456,"id":"CVE-2026-89699","ts":1790005706244,"field":"severity","old":"high","new":"medium"},{"seq":197732,"id":"CVE-2026-89699","ts":1789384318600,"field":"cvss","old":"5.3","new":"7.5"},{"seq":197731,"id":"CVE-2026-89699","ts":1789384318600,"field":"severity","old":"medium","new":"high"},{"seq":183347,"id":"CVE-2026-89699","ts":1789356674981,"field":"cvss","old":"7.5","new":"5.3"},{"seq":183346,"id":"CVE-2026-89699","ts":1789356674981,"field":"severity","old":"high","new":"medium"},{"seq":153582,"id":"CVE-2026-89699","ts":1789285351371,"field":"cvss","old":null,"new":"7.5"},{"seq":153581,"id":"CVE-2026-89699","ts":1789285351371,"field":"severity","old":"none","new":"high"},{"seq":147640,"id":"CVE-2026-89699","ts":1789270211701,"field":"cvss","old":null,"new":"5.3"},{"seq":147639,"id":"CVE-2026-89699","ts":1789270211701,"field":"severity","old":"none","new":"medium"},{"seq":109398,"id":"CVE-2026-89699","ts":1789183731760,"field":"cvss","old":null,"new":"5.3"},{"seq":109397,"id":"CVE-2026-89699","ts":1789183731760,"field":"severity","old":"none","new":"medium"}]}