{"id":"CVE-2026-64604","title":"KVM: VMX: Grab vmcs12 on CR8 interception update iff vCPU is in guest mode","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: VMX: Grab vmcs12 on CR8 interception update iff vCPU is in guest mode\n\nWhen updating CR8 intercepts, get vmcs12 if and only if the vCPU is in\nguest mode so that a …","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < c7cd3605244c924249dea32632e1bc3e89bda543","Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < 9a21f1defd96c6301c5fb462a78eb51b191bd2dd","Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < 570af5db081b87374594a00711ac5760d2ea6844","Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < ffaaff82336db84e9b58e7a3e81c2fd64e05ed7a","Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < 258ec63c0f281bf7b50f9de67c8e93b5b7be5ed4","Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < 3dcfb04dd43b16fa1240fc6487fff578ad57264c","Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < db8407b9fd06d857a4a5e8bcff1d086d13007711","Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < 7ef78d71ca713d8c00f7c34ddcf276c808143f77","Linux 3.18"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T16:42:06.934606Z"},"published":"2026-08-06","updated":"2026-11-06","sourceUpdated":"2026-11-06T16:44:58.242Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64604","references":[{"url":"https://git.kernel.org/stable/c/c7cd3605244c924249dea32632e1bc3e89bda543"},{"url":"https://git.kernel.org/stable/c/9a21f1defd96c6301c5fb462a78eb51b191bd2dd"},{"url":"https://git.kernel.org/stable/c/570af5db081b87374594a00711ac5760d2ea6844"},{"url":"https://git.kernel.org/stable/c/ffaaff82336db84e9b58e7a3e81c2fd64e05ed7a"},{"url":"https://git.kernel.org/stable/c/258ec63c0f281bf7b50f9de67c8e93b5b7be5ed4"},{"url":"https://git.kernel.org/stable/c/3dcfb04dd43b16fa1240fc6487fff578ad57264c"},{"url":"https://git.kernel.org/stable/c/db8407b9fd06d857a4a5e8bcff1d086d13007711"},{"url":"https://git.kernel.org/stable/c/7ef78d71ca713d8c00f7c34ddcf276c808143f77"}],"tags":["cve.org"],"epss":0.00171,"epssPercentile":0.06493,"ingestedAt":"2026-11-06T16:57:43.148Z","slug":"CVE-2026-64604","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nKVM: VMX: Grab vmcs12 on CR8 interception update iff vCPU is in guest mode\n\nWhen updating CR8 intercepts, get vmcs12 if and only if the vCPU is in\nguest mode so that a future change can have update CR8 intercepts during\nvCPU creation, without running afoul of get_vmcs12()'s lockdep assertion.\n\n  ------------[ cut here ]------------\n  debug_locks && !(lock_is_held(&(&vcpu->mutex)->dep_map) || !refcount_read(&vcpu->kvm->users_count))\n  WARNING: arch/x86/kvm/vmx/nested.h:61 at get_vmcs12 arch/x86/kvm/vmx/nested.h:60 [inline], CPU#0: syz.2.19/5879\n  WARNING: arch/x86/kvm/vmx/nested.h:61 at vmx_update_cr8_intercept+0x3de/0x4e0 arch/x86/kvm/vmx/vmx.c:6879, CPU#0: syz.2.19/5879\n  Modules linked in:\n  CPU: 0 UID: 0 PID: 5879 Comm: syz.2.19 Not tainted syzkaller #0 PREEMPT(full)\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014\n  RIP: 0010:get_vmcs12 arch/x86/kvm/vmx/nested.h:60 [inline]\n  RIP: 0010:vmx_update_cr8_intercept+0x3de/0x4e0 arch/x86/kvm/vmx/vmx.c:6879\n  Call Trace:\n   <TASK>\n   apic_update_ppr arch/x86/kvm/lapic.c:984 [inline]\n   kvm_lapic_reset+0x1c24/0x2980 arch/x86/kvm/lapic.c:3023\n   kvm_vcpu_reset+0x44c/0x1bf0 arch/x86/kvm/x86.c:12986\n   kvm_arch_vcpu_create+0x746/0x8b0 arch/x86/kvm/x86.c:12847\n   kvm_vm_ioctl_create_vcpu+0x428/0x930 virt/kvm/kvm_main.c:4201\n   kvm_vm_ioctl+0x893/0xd50 virt/kvm/kvm_main.c:5159\n   vfs_ioctl fs/ioctl.c:51 [inline]\n   __do_sys_ioctl fs/ioctl.c:597 [inline]\n   __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583\n   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n   do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n   </TASK>\n\nNo functional change intended.\n\n## Affected\n\n- `Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < c7cd3605244c924249dea32632e1bc3e89bda543`\n- `Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < 9a21f1defd96c6301c5fb462a78eb51b191bd2dd`\n- `Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < 570af5db081b87374594a00711ac5760d2ea6844`\n- `Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < ffaaff82336db84e9b58e7a3e81c2fd64e05ed7a`\n- `Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < 258ec63c0f281bf7b50f9de67c8e93b5b7be5ed4`\n- `Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < 3dcfb04dd43b16fa1240fc6487fff578ad57264c`\n- `Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < db8407b9fd06d857a4a5e8bcff1d086d13007711`\n- `Linux >= a7c0b07d570848e50fce4d31ac01313484d6b844 < 7ef78d71ca713d8c00f7c34ddcf276c808143f77`\n- `Linux 3.18`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}