{"id":"CVE-2026-89683","title":"nfsd: fix dentry ref leak on V4ROOT export filehandle lookup","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix dentry ref leak on V4ROOT export filehandle lookup\n\nnfsd_set_fh_dentry() leaks the dentry reference from\nexportfs_decode_fh_raw() when the NFS3_FHSIZE or NFS_…","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-911"],"vendor":"Linux","product":"Linux","affected":["Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < d493cf57f4c4dae5396cd6ad41e5c209d0615a81","Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < c1ae0f973bcba5730871e35976a0ab6878fdac34","Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < 11db8df188b34bdb8c6a3a0bf438e5fc8cd75aca","Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < 6247023fbbec1325029f2d5f2a7cdc0f9f9ea15a","Linux 6.12"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:50:56.607Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89683","references":[{"url":"https://git.kernel.org/stable/c/d493cf57f4c4dae5396cd6ad41e5c209d0615a81"},{"url":"https://git.kernel.org/stable/c/c1ae0f973bcba5730871e35976a0ab6878fdac34"},{"url":"https://git.kernel.org/stable/c/11db8df188b34bdb8c6a3a0bf438e5fc8cd75aca"},{"url":"https://git.kernel.org/stable/c/6247023fbbec1325029f2d5f2a7cdc0f9f9ea15a"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89683.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89683"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532313"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89683"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89683"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89683.mbox"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.00175,"epssPercentile":0.06998,"ingestedAt":"2026-09-14T11:11:19.885Z","slug":"CVE-2026-89683","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix dentry ref leak on V4ROOT export filehandle lookup\n\nnfsd_set_fh_dentry() leaks the dentry reference from\nexportfs_decode_fh_raw() when the NFS3_FHSIZE or NFS_FHSIZE\nswitch cases detect NFSEXP_V4ROOT and goto out. The out: label\ncalls exp_put() but never dput(dentry), and fhp->fh_dentry was\nnever assigned so fh_put() cannot compensate.\n\nA crafted NFSv3 filehandle targeting a V4ROOT export's fsid\ntriggers the leak on every request.\n\n## Affected\n\n- `Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < d493cf57f4c4dae5396cd6ad41e5c209d0615a81`\n- `Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < c1ae0f973bcba5730871e35976a0ab6878fdac34`\n- `Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < 11db8df188b34bdb8c6a3a0bf438e5fc8cd75aca`\n- `Linux >= ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < 6247023fbbec1325029f2d5f2a7cdc0f9f9ea15a`\n- `Linux 6.12`\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 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89683.json)","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":205472,"id":"CVE-2026-89683","ts":1789576721417,"field":"cvss","old":"5.9","new":"7"},{"seq":205471,"id":"CVE-2026-89683","ts":1789576721417,"field":"severity","old":"medium","new":"high"},{"seq":204013,"id":"CVE-2026-89683","ts":1789490231046,"field":"cvss","old":null,"new":"5.9"},{"seq":204012,"id":"CVE-2026-89683","ts":1789490231046,"field":"severity","old":"none","new":"medium"},{"seq":147387,"id":"CVE-2026-89683","ts":1789270210704,"field":"cvss","old":null,"new":"5.9"},{"seq":147386,"id":"CVE-2026-89683","ts":1789270210704,"field":"severity","old":"none","new":"medium"},{"seq":109133,"id":"CVE-2026-89683","ts":1789183730438,"field":"cvss","old":null,"new":"5.9"},{"seq":109132,"id":"CVE-2026-89683","ts":1789183730438,"field":"severity","old":"none","new":"medium"}]}