{"api_version":"1","generated_at":"2026-09-16T09:00:04+00:00","cve":"CVE-2026-64320","urls":{"html":"https://cve.report/CVE-2026-64320","api":"https://cve.report/api/cve/CVE-2026-64320.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-64320","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64320"},"summary":{"title":"nvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log Page","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log Page\n\nnvmet_execute_disc_get_log_page() validates only the dword alignment\nof the host-supplied Log Page Offset (lpo).  The 64-bit offset is then\nadded to a small kzalloc'd buffer that holds the discovery log page\nand the result is passed straight to nvmet_copy_to_sgl(), which\nmemcpy()s data_len bytes out to the host with no source-side bound\ncheck:\n\n    u64 offset      = nvmet_get_log_page_offset(req->cmd);  /* 64-bit host */\n    size_t data_len = nvmet_get_log_page_len(req->cmd);     /* 32-bit host */\n    ...\n    if (offset & 0x3) { ... }                               /* only check */\n    ...\n    alloc_len = sizeof(*hdr) + entry_size * discovery_log_entries(req);\n    buffer = kzalloc(alloc_len, GFP_KERNEL);\n    ...\n    status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len);\n\nThe Discovery controller is unauthenticated -- nvmet_host_allowed()\nreturns true unconditionally for the discovery subsystem -- so the call\nis reachable pre-authentication by any TCP/RDMA/FC peer that can reach\nthe nvmet target.  With a discovery log page of ~1 KiB, an attacker\nrequesting up to 4 KiB starting at offset == alloc_len reads the next\nslab page out and gets its content returned over the fabric (an\nempirical run on a default nvmet-tcp loopback target leaked 81\ncanonical kernel pointers in one Get Log Page response).  Pointing the\noffset at unmapped kernel memory faults the in-kernel memcpy and\ncrashes (or panics, on panic_on_oops=1) the target host instead.\n\nThe attacker-controlled source-side offset pattern\n\"nvmet_copy_to_sgl(req, 0, buffer + ATTACKER_OFFSET, ...)\" is unique\nto nvmet_execute_disc_get_log_page in the entire nvmet codebase: every\nother Get Log Page handler in admin-cmd.c either ignores lpo (and\nsilently starts every response at offset 0) or tracks a local\ndestination offset with a fixed source pointer.\n\nValidate the host-supplied offset against the log page size, cap the\ncopy length to what is actually available, and zero-fill any remainder\nof the host transfer buffer.  The zero-fill matches the existing\nshort-response pattern in nvmet_execute_get_log_changed_ns()\n(admin-cmd.c) and prevents leaking transport SGL contents when the\nhost asks for more bytes than the log page contains.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-25 10:17:13","updated_at":"2026-09-03 15:49:04"},"problem_types":["CWE-125"],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"9.1","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","baseScore":9.1,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"9.1","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","data":{"baseScore":9.1,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/56c021a0869260d04c4b65d1471936aaf9177114","name":"https://git.kernel.org/stable/c/56c021a0869260d04c4b65d1471936aaf9177114","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/53cd102a7a56079b11b897835bd9b94c14e6322c","name":"https://git.kernel.org/stable/c/53cd102a7a56079b11b897835bd9b94c14e6322c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/33b974eb626154ae9348f2bac7de84cb2a3d9dd4","name":"https://git.kernel.org/stable/c/33b974eb626154ae9348f2bac7de84cb2a3d9dd4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a29b316b9bbfd269f323ab4ba9906a894025680f","name":"https://git.kernel.org/stable/c/a29b316b9bbfd269f323ab4ba9906a894025680f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64320","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64320","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a07b4970f464f13640e28e16dad6cfa33647cc99 33b974eb626154ae9348f2bac7de84cb2a3d9dd4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a07b4970f464f13640e28e16dad6cfa33647cc99 56c021a0869260d04c4b65d1471936aaf9177114 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a07b4970f464f13640e28e16dad6cfa33647cc99 a29b316b9bbfd269f323ab4ba9906a894025680f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a07b4970f464f13640e28e16dad6cfa33647cc99 53cd102a7a56079b11b897835bd9b94c14e6322c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2026","cve_id":"64320","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"linux","cpe5":"linux_kernel","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"64320","cve":"CVE-2026-64320","epss":"0.007280000","percentile":"0.511440000","score_date":"2026-08-17","updated_at":"2026-08-18 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the Linux kernel, the following vulnerability has been resolved:\n\nnvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log Page\n\nnvmet_execute_disc_get_log_page() validates only the dword alignment\nof the host-supplied Log Page Offset (lpo).  The 64-bit offset is then\nadded to a small kzalloc'd buffer that holds the discovery log page\nand the result is passed straight to nvmet_copy_to_sgl(), which\nmemcpy()s data_len bytes out to the host with no source-side bound\ncheck:\n\n    u64 offset      = nvmet_get_log_page_offset(req->cmd);  /* 64-bit host */\n    size_t data_len = nvmet_get_log_page_len(req->cmd);     /* 32-bit host */\n    ...\n    if (offset & 0x3) { ... }                               /* only check */\n    ...\n    alloc_len = sizeof(*hdr) + entry_size * discovery_log_entries(req);\n    buffer = kzalloc(alloc_len, GFP_KERNEL);\n    ...\n    status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len);\n\nThe Discovery controller is unauthenticated -- nvmet_host_allowed()\nreturns true unconditionally for the discovery subsystem -- so the call\nis reachable pre-authentication by any TCP/RDMA/FC peer that can reach\nthe nvmet target.  With a discovery log page of ~1 KiB, an attacker\nrequesting up to 4 KiB starting at offset == alloc_len reads the next\nslab page out and gets its content returned over the fabric (an\nempirical run on a default nvmet-tcp loopback target leaked 81\ncanonical kernel pointers in one Get Log Page response).  Pointing the\noffset at unmapped kernel memory faults the in-kernel memcpy and\ncrashes (or panics, on panic_on_oops=1) the target host instead.\n\nThe attacker-controlled source-side offset pattern\n\"nvmet_copy_to_sgl(req, 0, buffer + ATTACKER_OFFSET, ...)\" is unique\nto nvmet_execute_disc_get_log_page in the entire nvmet codebase: every\nother Get Log Page handler in admin-cmd.c either ignores lpo (and\nsilently starts every response at offset 0) or tracks a local\ndestination offset with a fixed source pointer.\n\nValidate the host-supplied offset against the log page size, cap the\ncopy length to what is actually available, and zero-fill any remainder\nof the host transfer buffer.  The zero-fill matches the existing\nshort-response pattern in nvmet_execute_get_log_changed_ns()\n(admin-cmd.c) and prevents leaking transport SGL contents when the\nhost asks for more bytes than the log page contains."}],"metrics":[{"cvssV3_1":{"baseScore":9.1,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:N - The vulnerable discovery command is remotely reachable through routable NVMe/TCP, as well as NVMe/RDMA and FC transports.\nAC:L - The attacker controls the protocol sequence, transfer length, and aligned 64-bit offset, with no race or condition outside their control.\nPR:N - The discovery subsystem accepts every Host NQN and explicitly skips DH-HMAC-CHAP authentication, making the command reachable pre-authentication.\nUI:N - No victim action is required after the NVMe-oF target port is available.\nS:U - The disclosure and crash affect the vulnerable target kernel within the same security authority.\nC:H - The unbounded offset permits repeated multi-kilobyte kernel heap disclosures; testing cited by the fix exposed 81 canonical kernel pointers in one response.\nI:N - The primitive reads target memory into transport response pages but provides no attacker-selected write to target memory.\nA:H - An offset resolving to unmapped or noncanonical memory faults the in-kernel memcpy, causing an oops or target-host panic."}]}],"providerMetadata":{"dateUpdated":"2026-08-17T04:53:20.999Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/33b974eb626154ae9348f2bac7de84cb2a3d9dd4"},{"url":"https://git.kernel.org/stable/c/56c021a0869260d04c4b65d1471936aaf9177114"},{"url":"https://git.kernel.org/stable/c/a29b316b9bbfd269f323ab4ba9906a894025680f"},{"url":"https://git.kernel.org/stable/c/53cd102a7a56079b11b897835bd9b94c14e6322c"}],"title":"nvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log Page","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-64320","datePublished":"2026-07-25T08:49:48.908Z","dateReserved":"2026-07-19T15:36:31.780Z","dateUpdated":"2026-08-17T04:53:20.999Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-25 10:17:13","lastModifiedDate":"2026-09-03 15:49:04","problem_types":["CWE-125"],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","baseScore":9.1,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":5.2}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.12.96","matchCriteriaId":"51DDB3A2-C7C2-4C89-B438-74CE66BE0DFC"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.18.39","matchCriteriaId":"914AE4BC-3D59-4C5A-9DB5-9CE327B429F7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"7.1.4","matchCriteriaId":"6228DDD6-4557-4AA3-9F43-AB995D471E42"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"64320","Ordinal":"1","Title":"nvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log","CVE":"CVE-2026-64320","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"64320","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log Page\n\nnvmet_execute_disc_get_log_page() validates only the dword alignment\nof the host-supplied Log Page Offset (lpo).  The 64-bit offset is then\nadded to a small kzalloc'd buffer that holds the discovery log page\nand the result is passed straight to nvmet_copy_to_sgl(), which\nmemcpy()s data_len bytes out to the host with no source-side bound\ncheck:\n\n    u64 offset      = nvmet_get_log_page_offset(req->cmd);  /* 64-bit host */\n    size_t data_len = nvmet_get_log_page_len(req->cmd);     /* 32-bit host */\n    ...\n    if (offset & 0x3) { ... }                               /* only check */\n    ...\n    alloc_len = sizeof(*hdr) + entry_size * discovery_log_entries(req);\n    buffer = kzalloc(alloc_len, GFP_KERNEL);\n    ...\n    status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len);\n\nThe Discovery controller is unauthenticated -- nvmet_host_allowed()\nreturns true unconditionally for the discovery subsystem -- so the call\nis reachable pre-authentication by any TCP/RDMA/FC peer that can reach\nthe nvmet target.  With a discovery log page of ~1 KiB, an attacker\nrequesting up to 4 KiB starting at offset == alloc_len reads the next\nslab page out and gets its content returned over the fabric (an\nempirical run on a default nvmet-tcp loopback target leaked 81\ncanonical kernel pointers in one Get Log Page response).  Pointing the\noffset at unmapped kernel memory faults the in-kernel memcpy and\ncrashes (or panics, on panic_on_oops=1) the target host instead.\n\nThe attacker-controlled source-side offset pattern\n\"nvmet_copy_to_sgl(req, 0, buffer + ATTACKER_OFFSET, ...)\" is unique\nto nvmet_execute_disc_get_log_page in the entire nvmet codebase: every\nother Get Log Page handler in admin-cmd.c either ignores lpo (and\nsilently starts every response at offset 0) or tracks a local\ndestination offset with a fixed source pointer.\n\nValidate the host-supplied offset against the log page size, cap the\ncopy length to what is actually available, and zero-fill any remainder\nof the host transfer buffer.  The zero-fill matches the existing\nshort-response pattern in nvmet_execute_get_log_changed_ns()\n(admin-cmd.c) and prevents leaking transport SGL contents when the\nhost asks for more bytes than the log page contains.","Type":"Description","Title":"nvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log"}]}}}