CVE-2026-89658

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89658", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.743Z", "datePublished": "2026-09-11T19:45:46.857Z", "dateUpdated": "2026-10-19T08:50:29.852Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:50:29.852Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Prevent client use-after-free during NFSv4.0 revoked-state cleanup\n\nnfs40_clean_admin_revoked() takes a stateid reference under\nclp->cl_lock, drops nn->client_lock, and calls\nnfsd4_drop_revoked_stid(), which dereferences the stateid's client\nthrough s->sc_client->cl_lock. The stateid reference does not pin the\nclient, so a teardown racing the dropped lock can free the client\nwhile nfsd4_drop_revoked_stid() is still using it.\n\nThis cleanup runs from the laundromat, so a periodic sweep can race\nforce_expire_client() driven by a write to the clients/<id>/ctl file.\n\nSkip a client that is already expiring and otherwise pin it with\ncl_rpc_users under client_lock before dropping the lock, matching\nnfsd4_revoke_states()."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL"}, "scenarios": [{"lang": "en", "value": "AV:N - The UAF is in nfsd NFSv4.0 revoked-state cleanup (nfs40_clean_admin_revoked). A remote peer reaches it over TCP/2049 via nfsd_dispatch to nfsd4_proc_compound: SETCLIENTID/SETCLIENTID_CONFIRM (ALLOWED_WITHOUT_FH) call expire_client() while the laundromat still uses the client.\nAC:L - The attacker controls the expire side by retrying SETCLIENTID_CONFIRM around the known lease interval, or by inducing the documented clients/<id>/ctl expire of a misbehaving client. Cleanup drops client_lock without pinning cl_rpc_users, so mark_client_expired_locked succeeds; this is not a race outside attacker influence.\nPR:N - OP_SETCLIENTID and OP_SETCLIENTID_CONFIRM are ALLOWED_WITHOUT_FH/ALLOWED_ON_ABSENT_FS with no export check. Typical nfsd AUTH_SYS/AUTH_NULL deployments never verify RPC credentials, so any host that can reach TCP/2049 can create NFSv4.0 state and trigger the expire.\nUI:N - The attacker drives the NFS compounds that establish state and expire the client. Administrative revoke or ctl expire is a server operational condition (unexport or response to a misbehaving client), not a required victim user action.\nS:U - The freed object is struct nfs4_client in the NFS server kernel. Impact remains in that kernel security authority; there is no VM, IOMMU, or sandbox boundary crossing.\nC:H - nfsd4_drop_revoked_stid() and nfs4_put_stid() dereference s->sc_client after expire_client() frees the nfs4_client. Reclaim of that slab lets an attacker groom contents and disclose kernel memory. Per kernel guidance a UAF is C:H.\nI:H - nfs4_put_stid() lock-and-idr_remove on the freed client's cl_lock/cl_stateids, concurrent with __destroy_client() list walks, is a slab UAF write primitive usable for heap corruption and control-flow hijacking. Per kernel guidance a UAF is I:H.\nA:H - Use of the freed nfs4_client spinlock, IDR, and lists oopses or panics the nfsd host, fully denying service of the NFS server."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/nfsd/nfs4state.c"], "versions": [{"version": "d688d8585e6bea5e4e37f7497feea93b6b0a469c", "lessThan": "0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519", "status": "affected", "versionType": "git"}, {"version": "d688d8585e6bea5e4e37f7497feea93b6b0a469c", "lessThan": "b413ec5b23e3445dc9c4f273116078e2d4747626", "status": "affected", "versionType": "git"}, {"version": "d688d8585e6bea5e4e37f7497feea93b6b0a469c", "lessThan": "81cf7f1413862f87b078920c838460a6a88aa030", "status": "affected", "versionType": "git"}, {"version": "d688d8585e6bea5e4e37f7497feea93b6b0a469c", "lessThan": "7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55", "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/nfs4state.c"], "versions": [{"version": "6.9", "status": "affected"}, {"version": "0", "lessThan": "6.9", "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": "6.9", "versionEndExcluding": "6.12.109"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.18.50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519"}, {"url": "https://git.kernel.org/stable/c/b413ec5b23e3445dc9c4f273116078e2d4747626"}, {"url": "https://git.kernel.org/stable/c/81cf7f1413862f87b078920c838460a6a88aa030"}, {"url": "https://git.kernel.org/stable/c/7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55"}], "title": "NFSD: Prevent client use-after-free during NFSv4.0 revoked-state cleanup", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/nfsd/nfs4state.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519", "status": "affected", "version": "d688d8585e6bea5e4e37f7497feea93b6b0a469c", "versionType": "git"}, {"lessThan": "b413ec5b23e3445dc9c4f273116078e2d4747626", "status": "affected", "version": "d688d8585e6bea5e4e37f7497feea93b6b0a469c", "versionType": "git"}, {"lessThan": "81cf7f1413862f87b078920c838460a6a88aa030", "status": "affected", "version": "d688d8585e6bea5e4e37f7497feea93b6b0a469c", "versionType": "git"}, {"lessThan": "7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55", "status": "affected", "version": "d688d8585e6bea5e4e37f7497feea93b6b0a469c", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/nfsd/nfs4state.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.9"}, {"lessThan": "6.9", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.109", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.50", "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: Prevent client use-after-free during NFSv4.0 revoked-state cleanup\n\nnfs40_clean_admin_revoked() takes a stateid reference under\nclp->cl_lock, drops nn->client_lock, and calls\nnfsd4_drop_revoked_stid(), which dereferences the stateid's client\nthrough s->sc_client->cl_lock. The stateid reference does not pin the\nclient, so a teardown racing the dropped lock can free the client\nwhile nfsd4_drop_revoked_stid() is still using it.\n\nThis cleanup runs from the laundromat, so a periodic sweep can race\nforce_expire_client() driven by a write to the clients/<id>/ctl file.\n\nSkip a client that is already expiring and otherwise pin it with\ncl_rpc_users under client_lock before dropping the lock, matching\nnfsd4_revoke_states()."}], "id": "CVE-2026-89658", "lastModified": "2026-10-19T09:18:03.637", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-11T20:19:52.063", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/81cf7f1413862f87b078920c838460a6a88aa030"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b413ec5b23e3445dc9c4f273116078e2d4747626"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel NFSD: Denial of Service via use-after-free in NFSv4.0 cleanup", "id": "2532130", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532130"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.4", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["A flaw was found in the Linux kernel's Network File System Daemon (NFSD). During NFSv4.0 revoked-state cleanup, a race condition can occur where a client's state identifier (stateid) reference does not properly prevent the client from being prematurely freed while still in use. This use-after-free vulnerability could allow a remote attacker to cause a denial of service (DoS) or potentially execute arbitrary code on the affected system."], "name": "CVE-2026-89658", "public_date": "2026-09-11T19:45:46Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89658\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89658\nhttps://git.kernel.org/stable/c/0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519\nhttps://git.kernel.org/stable/c/7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55\nhttps://git.kernel.org/stable/c/81cf7f1413862f87b078920c838460a6a88aa030\nhttps://git.kernel.org/stable/c/b413ec5b23e3445dc9c4f273116078e2d4747626"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[d688d8585e6bea5e4e37f7497feea93b6b0a469c,0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[d688d8585e6bea5e4e37f7497feea93b6b0a469c,b413ec5b23e3445dc9c4f273116078e2d4747626)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[d688d8585e6bea5e4e37f7497feea93b6b0a469c,81cf7f1413862f87b078920c838460a6a88aa030)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[d688d8585e6bea5e4e37f7497feea93b6b0a469c,7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "6.9"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,6.9)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.109,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.50,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.4,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.3-rc1,*)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-12T06:15:04.246937+00:00", "updated": "2026-09-15T21:00:17.857498+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}