{"id":"CVE-2026-89689","title":"kernel: nfsd: don't free session slots that are still in use (CVE-2026-89689)","summary":"A flaw was found in the Linux kernel's Network File System (NFS) daemon, `nfsd`. A remote attacker could exploit a use-after-free vulnerability in the `nfsd4_sequence()` function. This occurs when the system attempts to reduce the number o…","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-825","vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","affected":["enterprise_linux 10","enterprise_linux 6"],"published":"2026-09-11","updated":"2026-09-15","sourceUpdated":"2026-09-15T11:30:21+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89689.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89689.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89689"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532497"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89689"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89689"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89689.mbox"},{"url":"https://git.kernel.org/stable/c/72d40b103bb03f0124d3a3c8f71a30cbafaf6afa"},{"url":"https://git.kernel.org/stable/c/b449b134e7762ddf98653a4b1d3e76d2d212ea64"},{"url":"https://git.kernel.org/stable/c/f5d22e372f4ac3eb287037a488c29691d52a6330"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00605,"epssPercentile":0.47648,"scores":{"vendor":7.4,"cna":9.8},"ingestedAt":"2026-09-14T15:23:07.473Z","slug":"CVE-2026-89689","body":"## Overview\n\nA flaw was found in the Linux kernel's Network File System (NFS) daemon, `nfsd`. A remote attacker could exploit a use-after-free vulnerability in the `nfsd4_sequence()` function. This occurs when the system attempts to reduce the number of active session slots while a client is still using one of the slots being freed. Successful exploitation leads to memory corruption, which can result in a denial of service or other system instability.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89689.json)\n\n**kernel: nfsd: don't free session slots that are still in use** — rated Important by Red Hat. Released 2026-09-11, updated 2026-09-15.\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 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\nAffected","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":203900,"id":"CVE-2026-89689","ts":1789490217562,"field":"cvss","old":"7.4","new":"7"},{"seq":202980,"id":"CVE-2026-89689","ts":1789403733211,"field":"cvss","old":"9.8","new":"7.4"},{"seq":202979,"id":"CVE-2026-89689","ts":1789403733211,"field":"severity","old":"critical","new":"high"},{"seq":197738,"id":"CVE-2026-89689","ts":1789384318634,"field":"cvss","old":"7.4","new":"9.8"},{"seq":197737,"id":"CVE-2026-89689","ts":1789384318634,"field":"severity","old":"high","new":"critical"},{"seq":183675,"id":"CVE-2026-89689","ts":1789356676898,"field":"cvss","old":"9.8","new":"7.4"},{"seq":183674,"id":"CVE-2026-89689","ts":1789356676898,"field":"severity","old":"critical","new":"high"},{"seq":153568,"id":"CVE-2026-89689","ts":1789285351317,"field":"cvss","old":null,"new":"9.8"},{"seq":153567,"id":"CVE-2026-89689","ts":1789285351317,"field":"severity","old":"none","new":"critical"},{"seq":147165,"id":"CVE-2026-89689","ts":1789270198173,"field":"cvss","old":null,"new":"7.4"},{"seq":147164,"id":"CVE-2026-89689","ts":1789270198173,"field":"severity","old":"none","new":"high"},{"seq":108910,"id":"CVE-2026-89689","ts":1789183729504,"field":"cvss","old":null,"new":"7.4"},{"seq":108909,"id":"CVE-2026-89689","ts":1789183729504,"field":"severity","old":"none","new":"high"}]}