{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89685", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.749Z", "datePublished": "2026-09-11T19:46:07.116Z", "dateUpdated": "2026-10-21T12:48:20.051Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:48:20.051Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix clock domain mismatch in clients_still_reclaiming()\n\nclients_still_reclaiming() computes a deadline from nn->boot_time\n(CLOCK_REALTIME, ~1.7 billion) but compares it against\nktime_get_boottime_seconds() (CLOCK_BOOTTIME, seconds since boot).\nThe comparison is always false \u2014 it would take ~54 years of uptime\nfor BOOTTIME to exceed the REALTIME-derived deadline.\n\nThis means any client can hold the server in grace indefinitely by\nsending CLAIM_PREVIOUS OPEN requests, blocking all non-reclaim\noperations for all other clients.\n\nAdd boot_time_bt (CLOCK_BOOTTIME) alongside the existing boot_time\nand use it for the deadline computation. boot_time (CLOCK_REALTIME)\nis preserved for its cl_boot clientid-nonce role."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - nfsd processes NFSv4 COMPOUND OPEN over TCP (typically port 2049). A remote peer reaches clients_still_reclaiming() by sending CLAIM_PREVIOUS OPEN or reclaim LOCK, which sets NFSD_NET_SOMEBODY_RECLAIMED and prevents grace from ending.\nAC:L - The attacker fully controls the reclaim OPEN/LOCK RPCs that keep NFSD_NET_SOMEBODY_RECLAIMED set; no race or memory layout is required. Grace always starts with nfsd, and the broken REALTIME-vs-BOOTTIME deadline never fires, so the attacker can extend it at will.\nPR:N - Default nfsd exports accept AUTH_SYS/AUTH_NULL with no credentials. An unauthenticated network peer that is or becomes a recorded NFSv4 client can send CLAIM_PREVIOUS OPEN; no server account or capability is required.\nUI:N - Exploitation takes only attacker-sent NFSv4 RPCs after nfsd starts; no victim user action such as mounting or opening a file is required.\nS:U - The impact stays in the same kernel nfsd/lockd grace state. This is a service denial on the NFS server, not a VM, IOMMU, or sandbox boundary crossing.\nC:N - The bug only miscompares grace deadlines and extends the grace period. It does not disclose kernel memory or file contents.\nI:N - No unauthorized modification of kernel or file data occurs. Other clients are blocked from new mutating operations, which is an availability effect rather than an integrity violation.\nA:H - Successful reclaim OPENs hold nfsd in grace indefinitely because the double-lease deadline never expires, so non-reclaim OPEN/REMOVE/RENAME/SETXATTR and lockd grace return NFS4ERR_GRACE and fully deny NFSv4 service to other clients."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/nfsd/netns.h", "fs/nfsd/nfs4state.c"], "versions": [{"version": "20b7d86f29d39e8ae19bb29c24ffee70dc385ddf", "lessThan": "04c3e4456fe76e8d7c94171009df3165c3262c51", "status": "affected", "versionType": "git"}, {"version": "20b7d86f29d39e8ae19bb29c24ffee70dc385ddf", "lessThan": "e92e80c5b043108029bc729b30d12c37158fb9cb", "status": "affected", "versionType": "git"}, {"version": "20b7d86f29d39e8ae19bb29c24ffee70dc385ddf", "lessThan": "f9cec313efb2fd18d962aad738a4892bce806016", "status": "affected", "versionType": "git"}, {"version": "20b7d86f29d39e8ae19bb29c24ffee70dc385ddf", "lessThan": "9843649196221152b6e5d138a3ce859bdaae1d96", "status": "affected", "versionType": "git"}, {"version": "20b7d86f29d39e8ae19bb29c24ffee70dc385ddf", "lessThan": "09ea3eb9a518565f5bca386e81b993ed8825f5e8", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/nfsd/netns.h", "fs/nfsd/nfs4state.c"], "versions": [{"version": "5.6", "status": "affected"}, {"version": "0", "lessThan": "5.6", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.51", "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": "5.6", "versionEndExcluding": "6.6.160"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.12.111"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.18.51"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/04c3e4456fe76e8d7c94171009df3165c3262c51"}, {"url": "https://git.kernel.org/stable/c/e92e80c5b043108029bc729b30d12c37158fb9cb"}, {"url": "https://git.kernel.org/stable/c/f9cec313efb2fd18d962aad738a4892bce806016"}, {"url": "https://git.kernel.org/stable/c/9843649196221152b6e5d138a3ce859bdaae1d96"}, {"url": "https://git.kernel.org/stable/c/09ea3eb9a518565f5bca386e81b993ed8825f5e8"}], "title": "nfsd: fix clock domain mismatch in clients_still_reclaiming()", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-89685", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-16T19:25:59.702339Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:26:48.681Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-89685", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-16T19:25:59.702339Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:26:00.471Z"}}], "cna": {"title": "nfsd: fix clock domain mismatch in clients_still_reclaiming()", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 7.5, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}, "scenarios": [{"lang": "en", "value": "AV:N - nfsd processes NFSv4 COMPOUND OPEN over TCP (typically port 2049). A remote peer reaches clients_still_reclaiming() by sending CLAIM_PREVIOUS OPEN or reclaim LOCK, which sets NFSD_NET_SOMEBODY_RECLAIMED and prevents grace from ending.\nAC:L - The attacker fully controls the reclaim OPEN/LOCK RPCs that keep NFSD_NET_SOMEBODY_RECLAIMED set; no race or memory layout is required. Grace always starts with nfsd, and the broken REALTIME-vs-BOOTTIME deadline never fires, so the attacker can extend it at will.\nPR:N - Default nfsd exports accept AUTH_SYS/AUTH_NULL with no credentials. An unauthenticated network peer that is or becomes a recorded NFSv4 client can send CLAIM_PREVIOUS OPEN; no server account or capability is required.\nUI:N - Exploitation takes only attacker-sent NFSv4 RPCs after nfsd starts; no victim user action such as mounting or opening a file is required.\nS:U - The impact stays in the same kernel nfsd/lockd grace state. This is a service denial on the NFS server, not a VM, IOMMU, or sandbox boundary crossing.\nC:N - The bug only miscompares grace deadlines and extends the grace period. It does not disclose kernel memory or file contents.\nI:N - No unauthorized modification of kernel or file data occurs. Other clients are blocked from new mutating operations, which is an availability effect rather than an integrity violation.\nA:H - Successful reclaim OPENs hold nfsd in grace indefinitely because the double-lease deadline never expires, so non-reclaim OPEN/REMOVE/RENAME/SETXATTR and lockd grace return NFS4ERR_GRACE and fully deny NFSv4 service to other clients."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "20b7d86f29d39e8ae19bb29c24ffee70dc385ddf", "lessThan": "04c3e4456fe76e8d7c94171009df3165c3262c51", "versionType": "git"}, {"status": "affected", "version": "20b7d86f29d39e8ae19bb29c24ffee70dc385ddf", "lessThan": "e92e80c5b043108029bc729b30d12c37158fb9cb", "versionType": "git"}, {"status": "affected", "version": "20b7d86f29d39e8ae19bb29c24ffee70dc385ddf", "lessThan": "f9cec313efb2fd18d962aad738a4892bce806016", "versionType": "git"}, {"status": "affected", "version": "20b7d86f29d39e8ae19bb29c24ffee70dc385ddf", "lessThan": "9843649196221152b6e5d138a3ce859bdaae1d96", "versionType": "git"}, {"status": "affected", "version": "20b7d86f29d39e8ae19bb29c24ffee70dc385ddf", "lessThan": "09ea3eb9a518565f5bca386e81b993ed8825f5e8", "versionType": "git"}], "programFiles": ["fs/nfsd/netns.h", "fs/nfsd/nfs4state.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.6"}, {"status": "unaffected", "version": "0", "lessThan": "5.6", "versionType": "semver"}, {"status": "unaffected", "version": "6.6.160", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.111", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.51", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.2.4", "versionType": "semver", "lessThanOrEqual": "7.2.*"}, {"status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["fs/nfsd/netns.h", "fs/nfsd/nfs4state.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/04c3e4456fe76e8d7c94171009df3165c3262c51"}, {"url": "https://git.kernel.org/stable/c/e92e80c5b043108029bc729b30d12c37158fb9cb"}, {"url": "https://git.kernel.org/stable/c/f9cec313efb2fd18d962aad738a4892bce806016"}, {"url": "https://git.kernel.org/stable/c/9843649196221152b6e5d138a3ce859bdaae1d96"}, {"url": "https://git.kernel.org/stable/c/09ea3eb9a518565f5bca386e81b993ed8825f5e8"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix clock domain mismatch in clients_still_reclaiming()\n\nclients_still_reclaiming() computes a deadline from nn->boot_time\n(CLOCK_REALTIME, ~1.7 billion) but compares it against\nktime_get_boottime_seconds() (CLOCK_BOOTTIME, seconds since boot).\nThe comparison is always false \u2014 it would take ~54 years of uptime\nfor BOOTTIME to exceed the REALTIME-derived deadline.\n\nThis means any client can hold the server in grace indefinitely by\nsending CLAIM_PREVIOUS OPEN requests, blocking all non-reclaim\noperations for all other clients.\n\nAdd boot_time_bt (CLOCK_BOOTTIME) alongside the existing boot_time\nand use it for the deadline computation. boot_time (CLOCK_REALTIME)\nis preserved for its cl_boot clientid-nonce role."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.160", "versionStartIncluding": "5.6"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.111", "versionStartIncluding": "5.6"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.51", "versionStartIncluding": "5.6"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.2.4", "versionStartIncluding": "5.6"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.3", "versionStartIncluding": "5.6"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:48:20.051Z"}}}, "cveMetadata": {"cveId": "CVE-2026-89685", "state": "PUBLISHED", "dateUpdated": "2026-10-21T12:48:20.051Z", "dateReserved": "2026-09-11T19:38:34.749Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-09-11T19:46:07.116Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/nfsd/netns.h", "fs/nfsd/nfs4state.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "04c3e4456fe76e8d7c94171009df3165c3262c51", "status": "affected", "version": "20b7d86f29d39e8ae19bb29c24ffee70dc385ddf", "versionType": "git"}, {"lessThan": "e92e80c5b043108029bc729b30d12c37158fb9cb", "status": "affected", "version": "20b7d86f29d39e8ae19bb29c24ffee70dc385ddf", "versionType": "git"}, {"lessThan": "f9cec313efb2fd18d962aad738a4892bce806016", "status": "affected", "version": "20b7d86f29d39e8ae19bb29c24ffee70dc385ddf", "versionType": "git"}, {"lessThan": "9843649196221152b6e5d138a3ce859bdaae1d96", "status": "affected", "version": "20b7d86f29d39e8ae19bb29c24ffee70dc385ddf", "versionType": "git"}, {"lessThan": "09ea3eb9a518565f5bca386e81b993ed8825f5e8", "status": "affected", "version": "20b7d86f29d39e8ae19bb29c24ffee70dc385ddf", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/nfsd/netns.h", "fs/nfsd/nfs4state.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.6"}, {"lessThan": "5.6", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.160", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.111", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.51", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix clock domain mismatch in clients_still_reclaiming()\n\nclients_still_reclaiming() computes a deadline from nn->boot_time\n(CLOCK_REALTIME, ~1.7 billion) but compares it against\nktime_get_boottime_seconds() (CLOCK_BOOTTIME, seconds since boot).\nThe comparison is always false \u2014 it would take ~54 years of uptime\nfor BOOTTIME to exceed the REALTIME-derived deadline.\n\nThis means any client can hold the server in grace indefinitely by\nsending CLAIM_PREVIOUS OPEN requests, blocking all non-reclaim\noperations for all other clients.\n\nAdd boot_time_bt (CLOCK_BOOTTIME) alongside the existing boot_time\nand use it for the deadline computation. boot_time (CLOCK_REALTIME)\nis preserved for its cl_boot clientid-nonce role."}], "id": "CVE-2026-89685", "lastModified": "2026-10-21T13:20:20.960", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-89685", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T19:25:59.702339Z", "version": "2.0.3"}}]}, "published": "2026-09-11T20:19:55.420", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/04c3e4456fe76e8d7c94171009df3165c3262c51"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/09ea3eb9a518565f5bca386e81b993ed8825f5e8"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/9843649196221152b6e5d138a3ce859bdaae1d96"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e92e80c5b043108029bc729b30d12c37158fb9cb"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f9cec313efb2fd18d962aad738a4892bce806016"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel: NFS daemon denial of service via clock domain mismatch", "id": "2532214", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532214"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.3", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-1025", "details": ["A flaw was found in the Linux kernel's Network File System (NFS) daemon (nfsd). A clock domain mismatch in the `clients_still_reclaiming()` function allows a remote attacker to indefinitely hold the server in a grace period. By sending specific `CLAIM_PREVIOUS OPEN` requests, an attacker can block all non-reclaim operations for other clients, leading to a denial of service (DoS)."], "name": "CVE-2026-89685", "public_date": "2026-09-11T19:46:07Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89685\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89685\nhttps://git.kernel.org/stable/c/09ea3eb9a518565f5bca386e81b993ed8825f5e8\nhttps://git.kernel.org/stable/c/9843649196221152b6e5d138a3ce859bdaae1d96\nhttps://git.kernel.org/stable/c/f9cec313efb2fd18d962aad738a4892bce806016"], "threat_severity": "Moderate"}