{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89697", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.750Z", "datePublished": "2026-09-11T19:46:15.772Z", "dateUpdated": "2026-10-19T08:51:10.455Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:51:10.455Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: add fh_want_write() for early-verified SETATTR in nfsd_proc_setattr()\n\nThe BOTH_TIME_SET branch calls fh_verify() early so setattr_prepare()\ncan inspect the dentry. This causes nfsd_setattr() to skip\nfh_want_write(), so notify_change() runs without a mount write\nreference.\n\nAdd the missing fh_want_write() call after the early fh_verify()." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H", "baseScore": 9.1, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The bug is in nfsd_proc_setattr(), the in-kernel NFSv2 SETATTR handler. A remote client reaches it by sending an NFSv2 SETATTR RPC over TCP/UDP port 2049 with both atime and mtime set, so no local access to the server is required.\nAC:L - Crafting SETATTR with ATTR_ATIME_SET|ATTR_MTIME_SET and equal timestamps deterministically takes the early fh_verify() path so nfsd_setattr() skips fh_want_write(). The attacker fully controls the RPC; no race or uninfluenced memory layout is required.\nPR:N - Default nfsd exports accept AUTH_SYS and AUTH_NULL with no cryptographic authentication, so the client asserts uid/gid. Any host permitted by the export list can issue SETATTR; this matches prior nfsd CNA scoring as PR:N.\nUI:N - The attacking NFS client issues the SETATTR RPC itself. No administrator or end-user action on the server is required.\nS:U - notify_change() without a mount write reference affects only the exported filesystem in the same kernel security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:N - The defect is a missing mnt_want_write()/sb_start_write() around notify_change() and commit_metadata(). It does not leak kernel memory, pointers, or file contents beyond ordinary authorized NFS access.\nI:H - nfsd_permission's read-only check does not cover freeze state, so SETATTR including ATTR_SIZE truncate, mode, and ownership updates proceeds on a frozen export and in a remount-ro race, letting a client mutate files and corrupt snapshots when writes should be blocked.\nA:H - Skipping freeze protection lets setattr run during fsfreeze, which can deadlock (inode_lock versus sb_start_write ordering), trigger filesystem withdraw/asserts such as GFS2 adding buffers while frozen, and hang or crash the nfsd thread." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfsd/nfsproc.c" ], "versions": [ { "version": "cc265089ce1b176dde963c74b53593446ee7f99a", "lessThan": "3eec9d791968c177a4a8cda9af5c04f79dae09cb", "status": "affected", "versionType": "git" }, { "version": "cc265089ce1b176dde963c74b53593446ee7f99a", "lessThan": "9229d824b938f4fb0ea7a5dddade51735e6fe6f9", "status": "affected", "versionType": "git" }, { "version": "cc265089ce1b176dde963c74b53593446ee7f99a", "lessThan": "2150305134889fb2fc25228d35353bd2f6f29500", "status": "affected", "versionType": "git" }, { "version": "cc265089ce1b176dde963c74b53593446ee7f99a", "lessThan": "d823bf9285cdf4514873b85ab5a888878dd4e8f4", "status": "affected", "versionType": "git" }, { "version": "cc265089ce1b176dde963c74b53593446ee7f99a", "lessThan": "15ca3b64a69caa6194bed8f98a20ed90a11c11dd", "status": "affected", "versionType": "git" }, { "version": "cc265089ce1b176dde963c74b53593446ee7f99a", "lessThan": "533964d420d385e11b08dd4c56c66ef5dcccaf08", "status": "affected", "versionType": "git" }, { "version": "cc265089ce1b176dde963c74b53593446ee7f99a", "lessThan": "c4a409b86a92815181a8e9395c6bf1696ad19175", "status": "affected", "versionType": "git" }, { "version": "cc265089ce1b176dde963c74b53593446ee7f99a", "lessThan": "4e475be769aa9f7a2c1ce55a2b8592cfccacddcc", "status": "affected", "versionType": "git" }, { "version": "1cb57d81cf20fe24b9e2e1daf57bfbdc24b77cd8", "status": "affected", "versionType": "git" }, { "version": "3.18.46", "lessThan": "3.19", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfsd/nfsproc.c" ], "versions": [ { "version": "4.2", "status": "affected" }, { "version": "0", "lessThan": "4.2", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.270", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "7.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.18.46" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/3eec9d791968c177a4a8cda9af5c04f79dae09cb" }, { "url": "https://git.kernel.org/stable/c/9229d824b938f4fb0ea7a5dddade51735e6fe6f9" }, { "url": "https://git.kernel.org/stable/c/2150305134889fb2fc25228d35353bd2f6f29500" }, { "url": "https://git.kernel.org/stable/c/d823bf9285cdf4514873b85ab5a888878dd4e8f4" }, { "url": "https://git.kernel.org/stable/c/15ca3b64a69caa6194bed8f98a20ed90a11c11dd" }, { "url": "https://git.kernel.org/stable/c/533964d420d385e11b08dd4c56c66ef5dcccaf08" }, { "url": "https://git.kernel.org/stable/c/c4a409b86a92815181a8e9395c6bf1696ad19175" }, { "url": "https://git.kernel.org/stable/c/4e475be769aa9f7a2c1ce55a2b8592cfccacddcc" } ], "title": "nfsd: add fh_want_write() for early-verified SETATTR in nfsd_proc_setattr()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-89697", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:26:07.202992Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:26:48.967Z" } } ] } }