{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-64247 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-64247 is a high-severity use after free vulnerability in Linux kernel, published on 24 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-64247 and fix it if it is affected.\n\nWhat it is: CVE-2026-64247 is a high-severity use after free vulnerability in Linux kernel, published on 24 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-64247 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-64247/ (Markdown: https://insights.sbomify.com/CVE-2026-64247/index.md)","id":"CVE-2026-64247","markdown":"https://insights.sbomify.com/CVE-2026-64247/index.md","name":"CVE-2026-64247","record":{"aliases":["BELL-CVE-2026-64247","DEBIAN-CVE-2026-64247","GHSA-2rqc-j7rg-xg47","ROOT-OS-UBUNTU-2204-CVE-2026-64247","UBUNTU-CVE-2026-64247"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","data_read"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel KVM","requires_auth":"low_privilege","summary":"A missing bounds check in KVM Hyper-V TLB flush handling allows out-of-bounds reads, potentially causing kernel crashes or information leaks.","user_interaction":"not_required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":8.4,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-125","name":"Out-of-bounds Read"}],"description":"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   \u003cTASK\u003e\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   \u003c/TASK\u003e\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  \u003effff88811ba5f580: 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]","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"KVM: x86: hyper-v: Bound the bank index when querying sparse banks","id":"CVE-2026-64247","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"use_after_free","year":"2026"},"n_packages":0,"n_references":5,"next":{"headline":"MIPS: smp: report dying CPU to RCU in stop_this_cpu()","id":"CVE-2026-64248"},"packages":[],"prev":{"headline":"power: reset: linkstation-poweroff: fix use-after-free in the linkstation_poweroff_init()","id":"CVE-2026-64246"},"products":["Linux"],"published":"2026-07-24","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A missing bounds check in KVM Hyper-V TLB flush handling allows out-of-bounds reads, potentially causing kernel crashes or information leaks.","url":"https://insights.sbomify.com/CVE-2026-64247/"}