{"id":"CVE-2026-89713","title":"kernel: NFSD: check truncate permission under inode lock (CVE-2026-89713)","summary":"A flaw was found in the Linux kernel's Network File System Daemon (NFSD). A remote attacker, by sending a crafted file attribute modification request (SETATTR) while a file is being concurrently appended, could exploit a time-of-check to t…","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 7","enterprise_linux 8","enterprise_linux 9","openshift_container_platform 4","enterprise_linux 6"],"published":"2026-09-11","updated":"2026-09-21","sourceUpdated":"2026-09-21T16:29:47+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89713.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89713.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89713"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532459"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89713"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89713"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89713.mbox"},{"url":"https://git.kernel.org/stable/c/3afa17d93ba8c925f49370c816c6dae5112d8c24"},{"url":"https://git.kernel.org/stable/c/44086254479035de42ca3d286ecf25521d4e6325"},{"url":"https://git.kernel.org/stable/c/b778e0e0a16759f22a70579c3cf8d254a40d4a7f"},{"url":"https://git.kernel.org/stable/c/d8352da196349182e1afd5a93308256cddc0a97d"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00647,"epssPercentile":0.48744,"scores":{"vendor":6.8,"cna":9.1},"ingestedAt":"2026-09-14T15:23:07.472Z","slug":"CVE-2026-89713","body":"## Overview\n\nA flaw was found in the Linux kernel's Network File System Daemon (NFSD). A remote attacker, by sending a crafted file attribute modification request (SETATTR) while a file is being concurrently appended, could exploit a time-of-check to time-of-use (TOCTOU) vulnerability. This could lead to the unauthorized truncation of append-only files, potentially resulting in data loss.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4, Red Hat Enterprise Linux 6 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4, Red Hat Enterprise Linux 7, … · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89713.json)\n\n**kernel: NFSD: check truncate permission under inode lock** — rated Important 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 7\n- Red Hat Enterprise Linux 8\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n- Red Hat Enterprise Linux 6\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n\n## Remediation\n\nFix deferred","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":208560,"id":"CVE-2026-89713","ts":1790009090750,"field":"cvss","old":"6.8","new":"7"},{"seq":208559,"id":"CVE-2026-89713","ts":1790009090750,"field":"severity","old":"medium","new":"high"},{"seq":202814,"id":"CVE-2026-89713","ts":1789403731480,"field":"cvss","old":"9.1","new":"6.8"},{"seq":202813,"id":"CVE-2026-89713","ts":1789403731480,"field":"severity","old":"critical","new":"medium"},{"seq":197704,"id":"CVE-2026-89713","ts":1789384318479,"field":"cvss","old":"6.8","new":"9.1"},{"seq":197703,"id":"CVE-2026-89713","ts":1789384318479,"field":"severity","old":"medium","new":"critical"},{"seq":183337,"id":"CVE-2026-89713","ts":1789356674934,"field":"cvss","old":"9.1","new":"6.8"},{"seq":183336,"id":"CVE-2026-89713","ts":1789356674934,"field":"severity","old":"critical","new":"medium"},{"seq":153604,"id":"CVE-2026-89713","ts":1789285351460,"field":"cvss","old":null,"new":"9.1"},{"seq":153603,"id":"CVE-2026-89713","ts":1789285351460,"field":"severity","old":"none","new":"critical"},{"seq":147153,"id":"CVE-2026-89713","ts":1789270197353,"field":"cvss","old":null,"new":"6.8"},{"seq":147152,"id":"CVE-2026-89713","ts":1789270197353,"field":"severity","old":"none","new":"medium"},{"seq":108904,"id":"CVE-2026-89713","ts":1789183729479,"field":"cvss","old":null,"new":"6.8"},{"seq":108903,"id":"CVE-2026-89713","ts":1789183729479,"field":"severity","old":"none","new":"medium"}]}