CVE-2026-89632

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89632", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.738Z", "datePublished": "2026-09-11T19:45:27.325Z", "dateUpdated": "2026-10-21T12:48:04.460Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:48:04.460Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix use-before-check of ReparseDataLength in reparse_buf_ptr()\n\nreparse_buf_ptr() reads buf->ReparseDataLength before checking that\ncount covers the full fixed header:\n\n buf = (struct reparse_data_buffer *)((u8 *)io + off);\n len = sizeof(*buf); /* 8 bytes */\n rdlen = le16_to_cpu(buf->ReparseDataLength); /* offset 4, 2 bytes */\n\n if (count < len || count < rdlen + len) /* check comes after */\n\nstruct reparse_data_buffer has ReparseDataLength at offset 4. If a\nserver returns OutputCount < 6, the read at offset 4-5 reaches past\nthe end of the received data. The off+count bounds against iov_len\nwere already validated, but that does not protect against count being\nsmaller than sizeof(*buf).\n\nSplit the check: verify count >= sizeof(*buf) before reading\nReparseDataLength, then verify count covers the data region."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H", "baseScore": 8.2, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - The flaw is in the in-kernel SMB client parser for FSCTL_GET_REPARSE_POINT IOCTL replies on TCP/445. A malicious, compromised, or on-path SMB server reaches reparse_buf_ptr() with crafted OutputOffset/OutputCount; this matches sibling client response-parsing scores such as CVE-2026-46155 and CVE-2024-49996.\nAC:L - The server fully controls OutputOffset and OutputCount. A successful IOCTL PDU with OutputCount < 6 and OutputOffset near iov_len (for example a 448-byte cifs_small_rq-sized frame) deterministically loads ReparseDataLength past the received payload, with no race or attacker-uncontrollable layout.\nPR:N - The attacker is the remote SMB server (or a MITM on an unsigned session) and needs no account, credentials, or capabilities on the victim client. GET_REPARSE runs on an already established tree connect after ordinary CREATE/lookup; the client authenticates to the server, not the reverse.\nUI:N - On an already-mounted or automounted CIFS share, any routine lookup/stat of a reparse point \u2014 including files the server flags as reparse in CREATE \u2014 issues FSCTL_GET_REPARSE_POINT. Backup jobs, indexers, and inode revalidation hit the parser with no contemporaneous victim mount action.\nS:U - The two-byte out-of-bounds load and any resulting oops stay inside the client kernel's security authority. The bug does not cross a VM, IOMMU, or sandbox boundary.\nC:L - The use-before-check reads exactly two bytes of ReparseDataLength past the IOCTL output region (and, when the PDU fills cifs_small_rq, past that 448-byte slab). Those bytes are passed only to smb_EIO2 tracing, so disclosure is strictly bounded, matching CVE-2026-64448 rather than unbounded heap leaks.\nI:N - The out-of-bounds access is a u16 load used only in the subsequent length check and error trace. On failure the helper returns -EIO and does not install a reparse tag or copy payload, so there is no kernel write or metadata-corruption primitive.\nA:H - A PDU that fills the cifs_small_rq or cifs_request slab with OutputOffset at the object end makes the two-byte load a true slab-out-of-bounds access, which KASAN reports as a BUG and which can oops/panic if the next page is unmapped. A malicious server can retrigger it on every GET_REPARSE."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/client/smb2inode.c"], "versions": [{"version": "a158bb66b1373866d9fd5997565a58a573085539", "lessThan": "b70bc592afd19732e2e4563300ebe8f974280365", "status": "affected", "versionType": "git"}, {"version": "67ec9949b0dfe78c99e110dd975eb7dc5645630c", "lessThan": "711cf71300d7992f450600df8864917d3538679f", "status": "affected", "versionType": "git"}, {"version": "67ec9949b0dfe78c99e110dd975eb7dc5645630c", "lessThan": "05f78e6cf34ea3a285053bd5999e08e8ac298bd5", "status": "affected", "versionType": "git"}, {"version": "6.6.32", "lessThan": "6.6.160", "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/smb/client/smb2inode.c"], "versions": [{"version": "6.8", "status": "affected"}, {"version": "0", "lessThan": "6.8", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.160", "lessThanOrEqual": "6.6.*", "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": "6.6.32", "versionEndExcluding": "6.6.160"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/b70bc592afd19732e2e4563300ebe8f974280365"}, {"url": "https://git.kernel.org/stable/c/711cf71300d7992f450600df8864917d3538679f"}, {"url": "https://git.kernel.org/stable/c/05f78e6cf34ea3a285053bd5999e08e8ac298bd5"}], "title": "smb: client: fix use-before-check of ReparseDataLength in reparse_buf_ptr()", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-89632", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-16T19:24:44.423758Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:26:45.525Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-89632", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-16T19:24:44.423758Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:24:45.767Z"}}], "cna": {"title": "smb: client: fix use-before-check of ReparseDataLength in reparse_buf_ptr()", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 8.2, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H"}, "scenarios": [{"lang": "en", "value": "AV:N - The flaw is in the in-kernel SMB client parser for FSCTL_GET_REPARSE_POINT IOCTL replies on TCP/445. A malicious, compromised, or on-path SMB server reaches reparse_buf_ptr() with crafted OutputOffset/OutputCount; this matches sibling client response-parsing scores such as CVE-2026-46155 and CVE-2024-49996.\nAC:L - The server fully controls OutputOffset and OutputCount. A successful IOCTL PDU with OutputCount < 6 and OutputOffset near iov_len (for example a 448-byte cifs_small_rq-sized frame) deterministically loads ReparseDataLength past the received payload, with no race or attacker-uncontrollable layout.\nPR:N - The attacker is the remote SMB server (or a MITM on an unsigned session) and needs no account, credentials, or capabilities on the victim client. GET_REPARSE runs on an already established tree connect after ordinary CREATE/lookup; the client authenticates to the server, not the reverse.\nUI:N - On an already-mounted or automounted CIFS share, any routine lookup/stat of a reparse point \u2014 including files the server flags as reparse in CREATE \u2014 issues FSCTL_GET_REPARSE_POINT. Backup jobs, indexers, and inode revalidation hit the parser with no contemporaneous victim mount action.\nS:U - The two-byte out-of-bounds load and any resulting oops stay inside the client kernel's security authority. The bug does not cross a VM, IOMMU, or sandbox boundary.\nC:L - The use-before-check reads exactly two bytes of ReparseDataLength past the IOCTL output region (and, when the PDU fills cifs_small_rq, past that 448-byte slab). Those bytes are passed only to smb_EIO2 tracing, so disclosure is strictly bounded, matching CVE-2026-64448 rather than unbounded heap leaks.\nI:N - The out-of-bounds access is a u16 load used only in the subsequent length check and error trace. On failure the helper returns -EIO and does not install a reparse tag or copy payload, so there is no kernel write or metadata-corruption primitive.\nA:H - A PDU that fills the cifs_small_rq or cifs_request slab with OutputOffset at the object end makes the two-byte load a true slab-out-of-bounds access, which KASAN reports as a BUG and which can oops/panic if the next page is unmapped. A malicious server can retrigger it on every GET_REPARSE."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "a158bb66b1373866d9fd5997565a58a573085539", "lessThan": "b70bc592afd19732e2e4563300ebe8f974280365", "versionType": "git"}, {"status": "affected", "version": "67ec9949b0dfe78c99e110dd975eb7dc5645630c", "lessThan": "711cf71300d7992f450600df8864917d3538679f", "versionType": "git"}, {"status": "affected", "version": "67ec9949b0dfe78c99e110dd975eb7dc5645630c", "lessThan": "05f78e6cf34ea3a285053bd5999e08e8ac298bd5", "versionType": "git"}, {"status": "affected", "version": "6.6.32", "lessThan": "6.6.160", "versionType": "semver"}], "programFiles": ["fs/smb/client/smb2inode.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.8"}, {"status": "unaffected", "version": "0", "lessThan": "6.8", "versionType": "semver"}, {"status": "unaffected", "version": "6.6.160", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "7.2.4", "versionType": "semver", "lessThanOrEqual": "7.2.*"}, {"status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["fs/smb/client/smb2inode.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/b70bc592afd19732e2e4563300ebe8f974280365"}, {"url": "https://git.kernel.org/stable/c/711cf71300d7992f450600df8864917d3538679f"}, {"url": "https://git.kernel.org/stable/c/05f78e6cf34ea3a285053bd5999e08e8ac298bd5"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix use-before-check of ReparseDataLength in reparse_buf_ptr()\n\nreparse_buf_ptr() reads buf->ReparseDataLength before checking that\ncount covers the full fixed header:\n\n buf = (struct reparse_data_buffer *)((u8 *)io + off);\n len = sizeof(*buf); /* 8 bytes */\n rdlen = le16_to_cpu(buf->ReparseDataLength); /* offset 4, 2 bytes */\n\n if (count < len || count < rdlen + len) /* check comes after */\n\nstruct reparse_data_buffer has ReparseDataLength at offset 4. If a\nserver returns OutputCount < 6, the read at offset 4-5 reaches past\nthe end of the received data. The off+count bounds against iov_len\nwere already validated, but that does not protect against count being\nsmaller than sizeof(*buf).\n\nSplit the check: verify count >= sizeof(*buf) before reading\nReparseDataLength, then verify count covers the data region."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.160", "versionStartIncluding": "6.6.32"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.2.4", "versionStartIncluding": "6.8"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.3", "versionStartIncluding": "6.8"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:48:04.460Z"}}}, "cveMetadata": {"cveId": "CVE-2026-89632", "state": "PUBLISHED", "dateUpdated": "2026-10-21T12:48:04.460Z", "dateReserved": "2026-09-11T19:38:34.738Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-09-11T19:45:27.325Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/smb/client/smb2inode.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "b70bc592afd19732e2e4563300ebe8f974280365", "status": "affected", "version": "a158bb66b1373866d9fd5997565a58a573085539", "versionType": "git"}, {"lessThan": "711cf71300d7992f450600df8864917d3538679f", "status": "affected", "version": "67ec9949b0dfe78c99e110dd975eb7dc5645630c", "versionType": "git"}, {"lessThan": "05f78e6cf34ea3a285053bd5999e08e8ac298bd5", "status": "affected", "version": "67ec9949b0dfe78c99e110dd975eb7dc5645630c", "versionType": "git"}, {"lessThan": "6.6.160", "status": "affected", "version": "6.6.32", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/smb/client/smb2inode.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.8"}, {"lessThan": "6.8", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.160", "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\nsmb: client: fix use-before-check of ReparseDataLength in reparse_buf_ptr()\n\nreparse_buf_ptr() reads buf->ReparseDataLength before checking that\ncount covers the full fixed header:\n\n buf = (struct reparse_data_buffer *)((u8 *)io + off);\n len = sizeof(*buf); /* 8 bytes */\n rdlen = le16_to_cpu(buf->ReparseDataLength); /* offset 4, 2 bytes */\n\n if (count < len || count < rdlen + len) /* check comes after */\n\nstruct reparse_data_buffer has ReparseDataLength at offset 4. If a\nserver returns OutputCount < 6, the read at offset 4-5 reaches past\nthe end of the received data. The off+count bounds against iov_len\nwere already validated, but that does not protect against count being\nsmaller than sizeof(*buf).\n\nSplit the check: verify count >= sizeof(*buf) before reading\nReparseDataLength, then verify count covers the data region."}], "id": "CVE-2026-89632", "lastModified": "2026-10-21T13:20:10.423", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.2, "baseSeverity": "HIGH", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 4.2, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-89632", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T19:24:44.423758Z", "version": "2.0.3"}}]}, "published": "2026-09-11T20:19:48.763", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/05f78e6cf34ea3a285053bd5999e08e8ac298bd5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/711cf71300d7992f450600df8864917d3538679f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b70bc592afd19732e2e4563300ebe8f974280365"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel SMB client: Out-of-bounds read vulnerability", "id": "2532415", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532415"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.3", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:H", "status": "draft"}, "cwe": "CWE-125", "details": ["A flaw was found in the Linux kernel's Server Message Block (SMB) client. A malicious server could exploit this vulnerability by sending specially crafted data, leading to an out-of-bounds read. This occurs because the `reparse_buf_ptr()` function reads data before properly validating the buffer size, allowing it to access memory beyond the intended boundary."], "name": "CVE-2026-89632", "public_date": "2026-09-11T19:45:27Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89632\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89632\nhttps://git.kernel.org/stable/c/05f78e6cf34ea3a285053bd5999e08e8ac298bd5\nhttps://git.kernel.org/stable/c/711cf71300d7992f450600df8864917d3538679f"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[a158bb66b1373866d9fd5997565a58a573085539,711cf71300d7992f450600df8864917d3538679f)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[a158bb66b1373866d9fd5997565a58a573085539,05f78e6cf34ea3a285053bd5999e08e8ac298bd5)"}}], "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": "[6.6.32,7.2.4)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.6.32,7.3-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": "2026-09-12T10:00:08.636096+00:00", "updated": "2026-09-15T21:15:14.620367+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}