CVE-2026-64247

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64247", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.772Z", "datePublished": "2026-07-24T15:31:15.304Z", "dateUpdated": "2026-10-19T20:28:16.498Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:51:58.515Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: hyper-v: Bound the bank index when querying sparse banks\n\nWhen checking if a VP ID is included in a sparse bank set, explicitly check\nthat the ID can actually be contained in a sparse bank (the TLFS allows for\na maximum of 64 banks of 64 vCPUs each). When handling a paravirtual TLB\nflush for L2, the VP ID is copied verbatim from the enlightened VMCS,\nwithout any bounds check, i.e. isn't guaranteed to be under the limit of\n4096.\n\nFailure to check the bounds of the VP ID leads to an out-of-bounds read\nwhen testing the sparse bank, and super strictly speaking could lead to KVM\nperforming an unnecessary TLB flush for an L2 vCPU.\n\n ==================================================================\n BUG: KASAN: use-after-free in hv_is_vp_in_sparse_set+0x85/0x100 [kvm]\n Read of size 8 at addr ffff88811ba5f598 by task hyperv_evmcs/2802\n\n CPU: 12 UID: 1000 PID: 2802 Comm: hyperv_evmcs Not tainted 7.1.0-rc2 #7 PREEMPT\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\n Call Trace:\n <TASK>\n dump_stack_lvl+0x51/0x60\n print_report+0xcb/0x5d0\n kasan_report+0xb4/0xe0\n kasan_check_range+0x35/0x1b0\n hv_is_vp_in_sparse_set+0x85/0x100 [kvm]\n kvm_hv_flush_tlb+0xe9e/0x16c0 [kvm]\n kvm_hv_hypercall+0xe6b/0x1e60 [kvm]\n vmx_handle_exit+0x485/0x1b60 [kvm_intel]\n kvm_arch_vcpu_ioctl_run+0x22e3/0x5070 [kvm]\n kvm_vcpu_ioctl+0x5d0/0x10c0 [kvm]\n __x64_sys_ioctl+0x129/0x1a0\n do_syscall_64+0xb9/0xcf0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53\n RIP: 0033:0x7f0e62d1a9bf\n </TASK>\n\n The buggy address belongs to the physical page:\n page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffffffffffffffff pfn:0x11ba5f\n flags: 0x4000000000000000(zone=1)\n raw: 4000000000000000 0000000000000000 00000000ffffffff 0000000000000000\n raw: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000000\n page dumped because: kasan: bad access detected\n\n Memory state around the buggy address:\n ffff88811ba5f480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ffff88811ba5f500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n >ffff88811ba5f580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ^\n ffff88811ba5f600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ffff88811ba5f680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ==================================================================\n Disabling lock debugging due to kernel taint\n\nOpportunistically add a compile time assertion to ensure the maximum number\nof sparse banks exactly matches the number of possible bits in the passed\nin mask.\n\n[sean: add KASAN splat, drop comment, add assert, massage changelog]"}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:H", "baseScore": 8.4, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - Triggering requires a Hyper-V TLB-flush hypercall from an L2 vCPU under KVM, ultimately reached through the local KVM_RUN ioctl; no network path reaches it.\nAC:L - A malicious nested-virtualization tenant controls both the unchecked enlightened-VMCS/VMCB VP ID and the sparse-bank hypercall data, with no uncontrollable race required.\nPR:L - The attacker needs control of a KVM guest with nested virtualization, or ordinary /dev/kvm access to create one, but requires neither host root nor an init-namespace capability.\nUI:N - Once the crafted nested guest executes, no action by another user is required.\nS:C - The out-of-bounds access occurs in the host kernel from attacker-controlled guest state, crossing the KVM guest-to-host isolation boundary.\nC:H - The attacker-selected VP ID makes test_bit() query selectable bits far beyond the stack-resident 64-bit mask, and the resulting TLB-flush decision can provide an oracle for host kernel memory.\nI:N - The primitive performs reads only; a set result merely selects a legitimate L2 vCPU for an extra TLB flush, with no out-of-bounds write or unsafe mapping change.\nA:H - The selectable access can reach a VMAP_STACK guard or another unmapped page and oops the host; KASAN already detects the access as an eight-byte invalid read, which can become a host-wide denial of service."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kvm/hyperv.c"], "versions": [{"version": "c58a318f6090efe06e6702b8882e2026f44f620e", "lessThan": "d18756b12aab30d07794446445c93112e5c69a2e", "status": "affected", "versionType": "git"}, {"version": "c58a318f6090efe06e6702b8882e2026f44f620e", "lessThan": "83c2f52c6a78b1590034e955cff3fe0b052fe4ae", "status": "affected", "versionType": "git"}, {"version": "c58a318f6090efe06e6702b8882e2026f44f620e", "lessThan": "e36095d8d922bb26ce860231aacf0cd14edea07c", "status": "affected", "versionType": "git"}, {"version": "c58a318f6090efe06e6702b8882e2026f44f620e", "lessThan": "f636cf6a1e7b7f40d48d8d08bd5f152aa61dd130", "status": "affected", "versionType": "git"}, {"version": "c58a318f6090efe06e6702b8882e2026f44f620e", "lessThan": "4721f8160f17554b003e8928bb61e6c9b2fe92a3", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kvm/hyperv.c"], "versions": [{"version": "6.2", "status": "affected"}, {"version": "0", "lessThan": "6.2", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.144", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.95", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.38", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.3", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "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": "6.2", "versionEndExcluding": "6.6.144"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.12.95"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.18.38"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "7.1.3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/d18756b12aab30d07794446445c93112e5c69a2e"}, {"url": "https://git.kernel.org/stable/c/83c2f52c6a78b1590034e955cff3fe0b052fe4ae"}, {"url": "https://git.kernel.org/stable/c/e36095d8d922bb26ce860231aacf0cd14edea07c"}, {"url": "https://git.kernel.org/stable/c/f636cf6a1e7b7f40d48d8d08bd5f152aa61dd130"}, {"url": "https://git.kernel.org/stable/c/4721f8160f17554b003e8928bb61e6c9b2fe92a3"}], "title": "KVM: x86: hyper-v: Bound the bank index when querying sparse banks", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-64247", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-16T15:37:54.586865Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-125", "description": "CWE-125 Out-of-bounds Read"}]}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-19T20:28:16.498Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-64247", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-16T15:37:54.586865Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-125", "description": "CWE-125 Out-of-bounds Read"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T15:37:55.345Z"}}], "cna": {"title": "KVM: x86: hyper-v: Bound the bank index when querying sparse banks", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 8.4, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:H"}, "scenarios": [{"lang": "en", "value": "AV:L - Triggering requires a Hyper-V TLB-flush hypercall from an L2 vCPU under KVM, ultimately reached through the local KVM_RUN ioctl; no network path reaches it.\nAC:L - A malicious nested-virtualization tenant controls both the unchecked enlightened-VMCS/VMCB VP ID and the sparse-bank hypercall data, with no uncontrollable race required.\nPR:L - The attacker needs control of a KVM guest with nested virtualization, or ordinary /dev/kvm access to create one, but requires neither host root nor an init-namespace capability.\nUI:N - Once the crafted nested guest executes, no action by another user is required.\nS:C - The out-of-bounds access occurs in the host kernel from attacker-controlled guest state, crossing the KVM guest-to-host isolation boundary.\nC:H - The attacker-selected VP ID makes test_bit() query selectable bits far beyond the stack-resident 64-bit mask, and the resulting TLB-flush decision can provide an oracle for host kernel memory.\nI:N - The primitive performs reads only; a set result merely selects a legitimate L2 vCPU for an extra TLB flush, with no out-of-bounds write or unsafe mapping change.\nA:H - The selectable access can reach a VMAP_STACK guard or another unmapped page and oops the host; KASAN already detects the access as an eight-byte invalid read, which can become a host-wide denial of service."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "c58a318f6090efe06e6702b8882e2026f44f620e", "lessThan": "d18756b12aab30d07794446445c93112e5c69a2e", "versionType": "git"}, {"status": "affected", "version": "c58a318f6090efe06e6702b8882e2026f44f620e", "lessThan": "83c2f52c6a78b1590034e955cff3fe0b052fe4ae", "versionType": "git"}, {"status": "affected", "version": "c58a318f6090efe06e6702b8882e2026f44f620e", "lessThan": "e36095d8d922bb26ce860231aacf0cd14edea07c", "versionType": "git"}, {"status": "affected", "version": "c58a318f6090efe06e6702b8882e2026f44f620e", "lessThan": "f636cf6a1e7b7f40d48d8d08bd5f152aa61dd130", "versionType": "git"}, {"status": "affected", "version": "c58a318f6090efe06e6702b8882e2026f44f620e", "lessThan": "4721f8160f17554b003e8928bb61e6c9b2fe92a3", "versionType": "git"}], "programFiles": ["arch/x86/kvm/hyperv.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.2"}, {"status": "unaffected", "version": "0", "lessThan": "6.2", "versionType": "semver"}, {"status": "unaffected", "version": "6.6.144", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.95", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.38", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.1.3", "versionType": "semver", "lessThanOrEqual": "7.1.*"}, {"status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["arch/x86/kvm/hyperv.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/d18756b12aab30d07794446445c93112e5c69a2e"}, {"url": "https://git.kernel.org/stable/c/83c2f52c6a78b1590034e955cff3fe0b052fe4ae"}, {"url": "https://git.kernel.org/stable/c/e36095d8d922bb26ce860231aacf0cd14edea07c"}, {"url": "https://git.kernel.org/stable/c/f636cf6a1e7b7f40d48d8d08bd5f152aa61dd130"}, {"url": "https://git.kernel.org/stable/c/4721f8160f17554b003e8928bb61e6c9b2fe92a3"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: hyper-v: Bound the bank index when querying sparse banks\n\nWhen checking if a VP ID is included in a sparse bank set, explicitly check\nthat the ID can actually be contained in a sparse bank (the TLFS allows for\na maximum of 64 banks of 64 vCPUs each). When handling a paravirtual TLB\nflush for L2, the VP ID is copied verbatim from the enlightened VMCS,\nwithout any bounds check, i.e. isn't guaranteed to be under the limit of\n4096.\n\nFailure to check the bounds of the VP ID leads to an out-of-bounds read\nwhen testing the sparse bank, and super strictly speaking could lead to KVM\nperforming an unnecessary TLB flush for an L2 vCPU.\n\n ==================================================================\n BUG: KASAN: use-after-free in hv_is_vp_in_sparse_set+0x85/0x100 [kvm]\n Read of size 8 at addr ffff88811ba5f598 by task hyperv_evmcs/2802\n\n CPU: 12 UID: 1000 PID: 2802 Comm: hyperv_evmcs Not tainted 7.1.0-rc2 #7 PREEMPT\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\n Call Trace:\n <TASK>\n dump_stack_lvl+0x51/0x60\n print_report+0xcb/0x5d0\n kasan_report+0xb4/0xe0\n kasan_check_range+0x35/0x1b0\n hv_is_vp_in_sparse_set+0x85/0x100 [kvm]\n kvm_hv_flush_tlb+0xe9e/0x16c0 [kvm]\n kvm_hv_hypercall+0xe6b/0x1e60 [kvm]\n vmx_handle_exit+0x485/0x1b60 [kvm_intel]\n kvm_arch_vcpu_ioctl_run+0x22e3/0x5070 [kvm]\n kvm_vcpu_ioctl+0x5d0/0x10c0 [kvm]\n __x64_sys_ioctl+0x129/0x1a0\n do_syscall_64+0xb9/0xcf0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53\n RIP: 0033:0x7f0e62d1a9bf\n </TASK>\n\n The buggy address belongs to the physical page:\n page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffffffffffffffff pfn:0x11ba5f\n flags: 0x4000000000000000(zone=1)\n raw: 4000000000000000 0000000000000000 00000000ffffffff 0000000000000000\n raw: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000000\n page dumped because: kasan: bad access detected\n\n Memory state around the buggy address:\n ffff88811ba5f480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ffff88811ba5f500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n >ffff88811ba5f580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ^\n ffff88811ba5f600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ffff88811ba5f680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ==================================================================\n Disabling lock debugging due to kernel taint\n\nOpportunistically add a compile time assertion to ensure the maximum number\nof sparse banks exactly matches the number of possible bits in the passed\nin mask.\n\n[sean: add KASAN splat, drop comment, add assert, massage changelog]"}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.144", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.95", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.38", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.1.3", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.2", "versionStartIncluding": "6.2"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:51:58.515Z"}}}, "cveMetadata": {"cveId": "CVE-2026-64247", "state": "PUBLISHED", "dateUpdated": "2026-10-19T20:28:16.498Z", "dateReserved": "2026-07-19T15:36:31.772Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-07-24T15:31:15.304Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["arch/x86/kvm/hyperv.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "d18756b12aab30d07794446445c93112e5c69a2e", "status": "affected", "version": "c58a318f6090efe06e6702b8882e2026f44f620e", "versionType": "git"}, {"lessThan": "83c2f52c6a78b1590034e955cff3fe0b052fe4ae", "status": "affected", "version": "c58a318f6090efe06e6702b8882e2026f44f620e", "versionType": "git"}, {"lessThan": "e36095d8d922bb26ce860231aacf0cd14edea07c", "status": "affected", "version": "c58a318f6090efe06e6702b8882e2026f44f620e", "versionType": "git"}, {"lessThan": "f636cf6a1e7b7f40d48d8d08bd5f152aa61dd130", "status": "affected", "version": "c58a318f6090efe06e6702b8882e2026f44f620e", "versionType": "git"}, {"lessThan": "4721f8160f17554b003e8928bb61e6c9b2fe92a3", "status": "affected", "version": "c58a318f6090efe06e6702b8882e2026f44f620e", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["arch/x86/kvm/hyperv.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.2"}, {"lessThan": "6.2", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.144", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.95", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.38", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.3", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "C8AD3BC8-C843-423C-B9DB-CB52F67F578E", "versionEndExcluding": "6.6.144", "versionStartIncluding": "6.2", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "4E206B86-E0E3-4394-A93F-39F2D50A8AA8", "versionEndExcluding": "6.12.95", "versionStartIncluding": "6.7", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "FA591B28-5D62-449E-BDBE-3C9391BF070A", "versionEndExcluding": "6.18.38", "versionStartIncluding": "6.13", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "9526B150-E2B3-4C6F-8AE5-1AF92B75AD9E", "versionEndExcluding": "7.1.3", "versionStartIncluding": "6.19", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: hyper-v: Bound the bank index when querying sparse banks\n\nWhen checking if a VP ID is included in a sparse bank set, explicitly check\nthat the ID can actually be contained in a sparse bank (the TLFS allows for\na maximum of 64 banks of 64 vCPUs each). When handling a paravirtual TLB\nflush for L2, the VP ID is copied verbatim from the enlightened VMCS,\nwithout any bounds check, i.e. isn't guaranteed to be under the limit of\n4096.\n\nFailure to check the bounds of the VP ID leads to an out-of-bounds read\nwhen testing the sparse bank, and super strictly speaking could lead to KVM\nperforming an unnecessary TLB flush for an L2 vCPU.\n\n ==================================================================\n BUG: KASAN: use-after-free in hv_is_vp_in_sparse_set+0x85/0x100 [kvm]\n Read of size 8 at addr ffff88811ba5f598 by task hyperv_evmcs/2802\n\n CPU: 12 UID: 1000 PID: 2802 Comm: hyperv_evmcs Not tainted 7.1.0-rc2 #7 PREEMPT\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\n Call Trace:\n <TASK>\n dump_stack_lvl+0x51/0x60\n print_report+0xcb/0x5d0\n kasan_report+0xb4/0xe0\n kasan_check_range+0x35/0x1b0\n hv_is_vp_in_sparse_set+0x85/0x100 [kvm]\n kvm_hv_flush_tlb+0xe9e/0x16c0 [kvm]\n kvm_hv_hypercall+0xe6b/0x1e60 [kvm]\n vmx_handle_exit+0x485/0x1b60 [kvm_intel]\n kvm_arch_vcpu_ioctl_run+0x22e3/0x5070 [kvm]\n kvm_vcpu_ioctl+0x5d0/0x10c0 [kvm]\n __x64_sys_ioctl+0x129/0x1a0\n do_syscall_64+0xb9/0xcf0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53\n RIP: 0033:0x7f0e62d1a9bf\n </TASK>\n\n The buggy address belongs to the physical page:\n page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffffffffffffffff pfn:0x11ba5f\n flags: 0x4000000000000000(zone=1)\n raw: 4000000000000000 0000000000000000 00000000ffffffff 0000000000000000\n raw: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000000\n page dumped because: kasan: bad access detected\n\n Memory state around the buggy address:\n ffff88811ba5f480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ffff88811ba5f500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n >ffff88811ba5f580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ^\n ffff88811ba5f600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ffff88811ba5f680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ==================================================================\n Disabling lock debugging due to kernel taint\n\nOpportunistically add a compile time assertion to ensure the maximum number\nof sparse banks exactly matches the number of possible bits in the passed\nin mask.\n\n[sean: add KASAN splat, drop comment, add assert, massage changelog]"}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nKVM: x86: hyper-v: Limitar el \u00edndice del banco al consultar bancos dispersos\n\nAl verificar si un ID de VP est\u00e1 incluido en un conjunto de bancos dispersos, verificar expl\u00edcitamente que el ID puede estar realmente contenido en un banco disperso (el TLFS permite un m\u00e1ximo de 64 bancos de 64 vCPU cada uno). Al manejar un vaciado de TLB paravirtual para L2, el ID de VP se copia textualmente del VMCS \u2019enlightened\u2019, sin ninguna comprobaci\u00f3n de l\u00edmites, es decir, no se garantiza que est\u00e9 por debajo del l\u00edmite de 4096.\n\nLa falta de comprobaci\u00f3n de los l\u00edmites del ID de VP conduce a una lectura fuera de l\u00edmites al probar el banco disperso y, en sentido estricto, podr\u00eda llevar a KVM a realizar un vaciado de TLB innecesario para una vCPU L2.\n\n ==================================================================\n BUG: KASAN: uso despu\u00e9s de liberaci\u00f3n en hv_is_vp_in_sparse_set+0x85/0x100 [kvm]\n Lectura de tama\u00f1o 8 en la direcci\u00f3n ffff88811ba5f598 por la tarea hyperv_evmcs/2802\n\n CPU: 12 UID: 1000 PID: 2802 Comm: hyperv_evmcs No contaminado 7.1.0-rc2 #7 PREEMPT\n Nombre del hardware: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\n Traza de llamadas:\n [TAREA]\n dump_stack_lvl+0x51/0x60\n print_report+0xcb/0x5d0\n kasan_report+0xb4/0xe0\n kasan_check_range+0x35/0x1b0\n hv_is_vp_in_sparse_set+0x85/0x100 [kvm]\n kvm_hv_flush_tlb+0xe9e/0x16c0 [kvm]\n kvm_hv_hypercall+0xe6b/0x1e60 [kvm]\n vmx_handle_exit+0x485/0x1b60 [kvm_intel]\n kvm_arch_vcpu_ioctl_run+0x22e3/0x5070 [kvm]\n kvm_vcpu_ioctl+0x5d0/0x10c0 [kvm]\n __x64_sys_ioctl+0x129/0x1a0\n do_syscall_64+0xb9/0xcf0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53\n RIP: 0033:0x7f0e62d1a9bf\n [/TAREA]\n\n La direcci\u00f3n err\u00f3nea pertenece a la p\u00e1gina f\u00edsica:\n p\u00e1gina: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffffffffffffffff pfn:0x11ba5f\n flags: 0x4000000000000000(zona=1)\n raw: 4000000000000000 0000000000000000 00000000ffffffff 0000000000000000\n raw: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000000\n p\u00e1gina volcada porque: kasan: acceso incorrecto detectado\n\n Estado de la memoria alrededor de la direcci\u00f3n err\u00f3nea:\n ffff88811ba5f480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ffff88811ba5f500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n >ffff88811ba5f580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ^\n ffff88811ba5f600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ffff88811ba5f680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ==================================================================\n Deshabilitando la depuraci\u00f3n de bloqueos debido a la contaminaci\u00f3n del kernel\n\nSe a\u00f1ade oportunamente una aserci\u00f3n en tiempo de compilaci\u00f3n para asegurar que el n\u00famero m\u00e1ximo de bancos dispersos coincide exactamente con el n\u00famero de bits posibles en la m\u00e1scara pasada.\n\n[sean: a\u00f1adir KASAN splat, eliminar comentario, a\u00f1adir aserci\u00f3n, ajustar registro de cambios]"}], "id": "CVE-2026-64247", "lastModified": "2026-11-08T16:10:00.183", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.4, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 2.0, "impactScore": 5.8, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-64247", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T15:37:54.586865Z", "version": "2.0.3"}}]}, "published": "2026-07-24T16:16:54.147", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/4721f8160f17554b003e8928bb61e6c9b2fe92a3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/83c2f52c6a78b1590034e955cff3fe0b052fe4ae"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/d18756b12aab30d07794446445c93112e5c69a2e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/e36095d8d922bb26ce860231aacf0cd14edea07c"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/f636cf6a1e7b7f40d48d8d08bd5f152aa61dd130"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-125"}], "source": "nvd@nist.gov", "type": "Primary"}, {"description": [{"lang": "en", "value": "CWE-125"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"bugzilla": {"description": "kernel: KVM: x86: hyper-v: Bound the bank index when querying sparse banks", "id": "2506797", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2506797"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-125", "details": ["No description is available for this CVE."], "name": "CVE-2026-64247", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-07-24T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-64247\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-64247\nhttps://lore.kernel.org/linux-cve-announce/2026072419-CVE-2026-64247-3d6b@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c58a318f6090efe06e6702b8882e2026f44f620e,d18756b12aab30d07794446445c93112e5c69a2e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c58a318f6090efe06e6702b8882e2026f44f620e,83c2f52c6a78b1590034e955cff3fe0b052fe4ae)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c58a318f6090efe06e6702b8882e2026f44f620e,e36095d8d922bb26ce860231aacf0cd14edea07c)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c58a318f6090efe06e6702b8882e2026f44f620e,f636cf6a1e7b7f40d48d8d08bd5f152aa61dd130)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c58a318f6090efe06e6702b8882e2026f44f620e,4721f8160f17554b003e8928bb61e6c9b2fe92a3)"}}], "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": "generic", "value": "6.2"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.2)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.144,6.7.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.95,6.13.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.38,6.19.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.3,7.2.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-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": "2026-07-24T22:00:13.913834+00:00", "updated": "2026-08-05T02:45:17.234446+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}