{"id":"CVE-2026-89660","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Prevent client use-after-free during admin state revocation\n\nA stateid holds only a bare pointer to its nfs4_client; a stateid\nreference does not pin it","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Prevent client use-after-free during admin state revocation\n\nA stateid holds only a bare pointer to its nfs4_client; a stateid\nreference does not pin it.  The cli…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-825"],"vendor":"Linux","product":"Linux","affected":["Linux >= 1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc < e1ba4d3c5bfdca3f013b8cbc829ae2f7975d8608","Linux >= 1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc < 549bd9868e9d77b07ea94870940d64342829c6ad","Linux >= 1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc < bf1f948691523282cc4905bc6cd325e0c0b49e6a","Linux >= 1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc < e270e5a0778e5bff852c8862ce9576ce70359393","Linux 6.9"],"published":"2026-09-11","updated":"2026-09-21","sourceUpdated":"2026-09-21T14:17:24.660","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-89660","references":[{"url":"https://git.kernel.org/stable/c/549bd9868e9d77b07ea94870940d64342829c6ad","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bf1f948691523282cc4905bc6cd325e0c0b49e6a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e1ba4d3c5bfdca3f013b8cbc829ae2f7975d8608","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e270e5a0778e5bff852c8862ce9576ce70359393","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89660.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89660"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532092"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89660"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89660"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89660.mbox"}],"tags":["nvd","cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00588,"epssPercentile":0.46567,"scores":{"nvd":9.8,"cna":9.8,"vendor":7},"ingestedAt":"2026-09-14T15:23:07.473Z","slug":"CVE-2026-89660","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Prevent client use-after-free during admin state revocation\n\nA stateid holds only a bare pointer to its nfs4_client; a stateid\nreference does not pin it.  The client survives only because\n__destroy_client() drains its stateids before free_client() runs.\n\nnfsd4_revoke_states() drops nn->client_lock across revoke_one_stid(),\nwhich dereferences the client to revoke a stateid and read\nclp->cl_minorversion.  A teardown racing the dropped lock can free\nthe client first.\n\nPinning cl_rpc_users under client_lock blocks the DESTROY_CLIENTID and\nEXCHANGE_ID teardown, which refuses while cl_rpc_users is non-zero.\nforce_expire_client() ignores it: once its wait for cl_rpc_users to\nreach zero has passed, a later pin goes unnoticed.\n\nUnder client_lock, skip a client whose cl_time is already zero --\nforce_expire_client() clears it there before waiting -- otherwise pin\ncl_rpc_users before dropping the lock.  The walk then either sees the\nexpiry and skips, or pins in time for that wait to cover the revoke.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\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 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89660.json)","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":208379,"id":"CVE-2026-89660","ts":1789997913776,"field":"cvss","old":"7","new":"9.8"},{"seq":208378,"id":"CVE-2026-89660","ts":1789997913776,"field":"severity","old":"high","new":"critical"},{"seq":208136,"id":"CVE-2026-89660","ts":1789922723056,"field":"cvss","old":"8.1","new":"7"},{"seq":203003,"id":"CVE-2026-89660","ts":1789403733308,"field":"cvss","old":"9.8","new":"8.1"},{"seq":203002,"id":"CVE-2026-89660","ts":1789403733308,"field":"severity","old":"critical","new":"high"},{"seq":197779,"id":"CVE-2026-89660","ts":1789384318816,"field":"cvss","old":"8.1","new":"9.8"},{"seq":197778,"id":"CVE-2026-89660","ts":1789384318816,"field":"severity","old":"high","new":"critical"},{"seq":183705,"id":"CVE-2026-89660","ts":1789356677034,"field":"cvss","old":"9.8","new":"8.1"},{"seq":183704,"id":"CVE-2026-89660","ts":1789356677034,"field":"severity","old":"critical","new":"high"},{"seq":153518,"id":"CVE-2026-89660","ts":1789285351118,"field":"cvss","old":null,"new":"9.8"},{"seq":153517,"id":"CVE-2026-89660","ts":1789285351118,"field":"severity","old":"none","new":"critical"},{"seq":147758,"id":"CVE-2026-89660","ts":1789270212176,"field":"cvss","old":null,"new":"8.1"},{"seq":147757,"id":"CVE-2026-89660","ts":1789270212176,"field":"severity","old":"none","new":"high"},{"seq":109520,"id":"CVE-2026-89660","ts":1789183732262,"field":"cvss","old":null,"new":"8.1"},{"seq":109519,"id":"CVE-2026-89660","ts":1789183732262,"field":"severity","old":"none","new":"high"}]}