{"id":"CVE-2026-89687","title":"nfsd: ensure nfsd_file_do_acquire() does not use a non-opened file","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: ensure nfsd_file_do_acquire() does not use a non-opened file\n\n->atomic_open is permitted to return success without actually opening\nthe file.  It indicates this b…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-908"],"vendor":"Linux","product":"Linux","affected":["Linux >= 64a989dbd144e0622371396461b11335459692d2 < a95a1cffacd0203100297001719160160f443dd6","Linux >= 64a989dbd144e0622371396461b11335459692d2 < 5859cc01fee06a2cd7458905a9593082fbab06e1","Linux 7.0"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:51:00.577Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89687","references":[{"url":"https://git.kernel.org/stable/c/a95a1cffacd0203100297001719160160f443dd6"},{"url":"https://git.kernel.org/stable/c/5859cc01fee06a2cd7458905a9593082fbab06e1"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89687.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89687"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532086"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89687"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89687"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89687.mbox"}],"tags":["cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00488,"epssPercentile":0.41785,"scores":{"cna":7.5,"vendor":5.5},"ingestedAt":"2026-09-14T15:23:07.472Z","slug":"CVE-2026-89687","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: ensure nfsd_file_do_acquire() does not use a non-opened file\n\n->atomic_open is permitted to return success without actually opening\nthe file.  It indicates this by calling finish_no_open().\nThis means dentry_create() can return a file which hasn't been opened.\nThis is extremely unlikely as ->atomic_open handlers typically\nuse finish_no_open() only for already existing files, and dentry_create()\nisn't called in that case, and the parent being locked should prevent\nraces.\n\nHowever out of an abundance of caution it seems wise to teach nfsd to\nonly use the file returned by dentry_create() if FMODE_OPENED is set,\nindicating that it has in fact been opened.\n\n## Affected\n\n- `Linux >= 64a989dbd144e0622371396461b11335459692d2 < a95a1cffacd0203100297001719160160f443dd6`\n- `Linux >= 64a989dbd144e0622371396461b11335459692d2 < 5859cc01fee06a2cd7458905a9593082fbab06e1`\n- `Linux 7.0`\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 OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat OpenShift Container Platform 4 · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89687.json)","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":224621,"id":"CVE-2026-89687","ts":1792401440127,"field":"cvss","old":"5.5","new":"7.5"},{"seq":224620,"id":"CVE-2026-89687","ts":1792401440127,"field":"severity","old":"medium","new":"high"},{"seq":208462,"id":"CVE-2026-89687","ts":1790005708190,"field":"cvss","old":"5.9","new":"5.5"},{"seq":202822,"id":"CVE-2026-89687","ts":1789403732547,"field":"cvss","old":"7.5","new":"5.9"},{"seq":202821,"id":"CVE-2026-89687","ts":1789403732547,"field":"severity","old":"high","new":"medium"},{"seq":197742,"id":"CVE-2026-89687","ts":1789384318650,"field":"cvss","old":"5.9","new":"7.5"},{"seq":197741,"id":"CVE-2026-89687","ts":1789384318650,"field":"severity","old":"medium","new":"high"},{"seq":183357,"id":"CVE-2026-89687","ts":1789356675028,"field":"cvss","old":"7.5","new":"5.9"},{"seq":183356,"id":"CVE-2026-89687","ts":1789356675028,"field":"severity","old":"high","new":"medium"},{"seq":153564,"id":"CVE-2026-89687","ts":1789285351301,"field":"cvss","old":null,"new":"7.5"},{"seq":153563,"id":"CVE-2026-89687","ts":1789285351301,"field":"severity","old":"none","new":"high"},{"seq":147694,"id":"CVE-2026-89687","ts":1789270211912,"field":"cvss","old":null,"new":"5.9"},{"seq":147693,"id":"CVE-2026-89687","ts":1789270211912,"field":"severity","old":"none","new":"medium"},{"seq":109448,"id":"CVE-2026-89687","ts":1789183731953,"field":"cvss","old":null,"new":"5.9"},{"seq":109447,"id":"CVE-2026-89687","ts":1789183731953,"field":"severity","old":"none","new":"medium"}]}