{"id":"CVE-2026-89712","title":"kernel: NFSD: restart ssc_expire_umount walk after dropping nfsd_ssc_lock (CVE-2026-89712)","summary":"A flaw was found in the Linux kernel's Network File System Daemon (NFSD) component. A race condition exists where, during the processing of unmounted source-server mounts, a thread may temporarily release a lock. During this window, anothe…","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 9","affected":["enterprise_linux 10","enterprise_linux 6","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-09-11","updated":"2026-09-21","sourceUpdated":"2026-09-21T17:07:07+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89712.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89712.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89712"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532255"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89712"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89712"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89712.mbox"},{"url":"https://git.kernel.org/stable/c/2b59029b8f24a99b5d844af2da3950d39d36eeea"},{"url":"https://git.kernel.org/stable/c/d9e151fea5ed706c1284adacabd869b0be745db2"},{"url":"https://git.kernel.org/stable/c/659ee3da073164e1e6e40dfcbc26eeed85845f93"},{"url":"https://git.kernel.org/stable/c/60680ae7243b22de3d09be990d8e23bcfc4af837"},{"url":"https://git.kernel.org/stable/c/77de363d9a1c8cd35f20482782c612cda085791a"},{"url":"https://git.kernel.org/stable/c/4ed8d2317aef21cc2a9e5a55d6b59860b4b151a8"},{"url":"https://git.kernel.org/stable/c/7377fa964b8aaf47cb04e5efcc4c82d15e8c2ce9"},{"url":"https://git.kernel.org/stable/c/036c1b182f4da65363e79ec0ac276edc6b7296e5"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00704,"epssPercentile":0.51477,"scores":{"vendor":7,"cna":9.8},"ingestedAt":"2026-09-14T15:23:07.449Z","slug":"CVE-2026-89712","body":"## Overview\n\nA flaw was found in the Linux kernel's Network File System Daemon (NFSD) component. A race condition exists where, during the processing of unmounted source-server mounts, a thread may temporarily release a lock. During this window, another NFS Remote Procedure Call (RPC) thread can free memory that the first thread subsequently attempts to access. This use-after-free vulnerability could allow a remote attacker to cause a denial of service.\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 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89712.json)\n\n**kernel: NFSD: restart ssc_expire_umount walk after dropping nfsd_ssc_lock** — 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 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 9\n- Red Hat OpenShift Container Platform 4\n\nNot affected:\n\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\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":208450,"id":"CVE-2026-89712","ts":1790005705018,"field":"cvss","old":"9.8","new":"7"},{"seq":208449,"id":"CVE-2026-89712","ts":1790005705018,"field":"severity","old":"critical","new":"high"},{"seq":197706,"id":"CVE-2026-89712","ts":1789384318487,"field":"cvss","old":"5.3","new":"9.8"},{"seq":197705,"id":"CVE-2026-89712","ts":1789384318487,"field":"severity","old":"medium","new":"critical"},{"seq":183655,"id":"CVE-2026-89712","ts":1789356676736,"field":"cvss","old":"9.8","new":"5.3"},{"seq":183654,"id":"CVE-2026-89712","ts":1789356676736,"field":"severity","old":"critical","new":"medium"},{"seq":153602,"id":"CVE-2026-89712","ts":1789285351452,"field":"cvss","old":null,"new":"9.8"},{"seq":153601,"id":"CVE-2026-89712","ts":1789285351452,"field":"severity","old":"none","new":"critical"},{"seq":147572,"id":"CVE-2026-89712","ts":1789270211435,"field":"cvss","old":null,"new":"5.3"},{"seq":147571,"id":"CVE-2026-89712","ts":1789270211435,"field":"severity","old":"none","new":"medium"},{"seq":109324,"id":"CVE-2026-89712","ts":1789183731429,"field":"cvss","old":null,"new":"5.3"},{"seq":109323,"id":"CVE-2026-89712","ts":1789183731429,"field":"severity","old":"none","new":"medium"}]}