CVE-2026-64604KVM: VMX: Grab vmcs12 on CR8 interception update iff vCPU is in guest mode

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Grab vmcs12 on CR8 interception update iff vCPU is in guest mode When updating CR8 intercepts, get vmcs12 if and only if the vCPU is in guest mode so that a future change can have update CR8 intercepts during vCPU creation, without running afoul of get_vmcs12()'s lockdep assertion. ------------[ cut here ]------------ debug_locks && !(lock_is_held(&(&vcpu->mutex)->dep_map) || !refcount_read(&vcpu->kvm->users_count)) 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 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 Modules linked in: CPU: 0 UID: 0 PID: 5879 Comm: syz.2.19 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:get_vmcs12 arch/x86/kvm/vmx/nested.h:60 [inline] RIP: 0010:vmx_update_cr8_intercept+0x3de/0x4e0 arch/x86/kvm/vmx/vmx.c:6879 Call Trace: <TASK> apic_update_ppr arch/x86/kvm/lapic.c:984 [inline] kvm_lapic_reset+0x1c24/0x2980 arch/x86/kvm/lapic.c:3023 kvm_vcpu_reset+0x44c/0x1bf0 arch/x86/kvm/x86.c:12986 kvm_arch_vcpu_create+0x746/0x8b0 arch/x86/kvm/x86.c:12847 kvm_vm_ioctl_create_vcpu+0x428/0x930 virt/kvm/kvm_main.c:4201 kvm_vm_ioctl+0x893/0xd50 virt/kvm/kvm_main.c:5159 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> No functional change intended.

Timeline

Scores

No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.

EPSS (exploitation in 30 days)

0.17% · top 93% of all CVEs (12 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.

Affected products

• Linux · Linux

  • affected a7c0b07d570848e50fce4d31ac01313484d6b844 – < c7cd3605244c924249dea32632e1bc3e89bda543
  • affected a7c0b07d570848e50fce4d31ac01313484d6b844 – < 9a21f1defd96c6301c5fb462a78eb51b191bd2dd
  • affected a7c0b07d570848e50fce4d31ac01313484d6b844 – < 570af5db081b87374594a00711ac5760d2ea6844
  • affected a7c0b07d570848e50fce4d31ac01313484d6b844 – < ffaaff82336db84e9b58e7a3e81c2fd64e05ed7a
  • affected a7c0b07d570848e50fce4d31ac01313484d6b844 – < 258ec63c0f281bf7b50f9de67c8e93b5b7be5ed4
  • affected a7c0b07d570848e50fce4d31ac01313484d6b844 – < 3dcfb04dd43b16fa1240fc6487fff578ad57264c
  • affected a7c0b07d570848e50fce4d31ac01313484d6b844 – < db8407b9fd06d857a4a5e8bcff1d086d13007711
  • affected a7c0b07d570848e50fce4d31ac01313484d6b844 – < 7ef78d71ca713d8c00f7c34ddcf276c808143f77

• Linux · Linux

  • affected 3.18
  • unaffected < 3.18
  • unaffected 5.10.261 – ≤ 5.10.*
  • unaffected 5.15.212 – ≤ 5.15.*
  • unaffected 6.1.178 – ≤ 6.1.*
  • unaffected 6.6.145 – ≤ 6.6.*
  • unaffected 6.12.96 – ≤ 6.12.*
  • unaffected 6.18.39 – ≤ 6.18.*
  • unaffected 7.1.4 – ≤ 7.1.*
  • unaffected 7.2 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-53790 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-64604](https://cveledger.app/badge/CVE-2026-64604.svg)](https://cveledger.app/cve/CVE-2026-64604)

Record last updated 6 Nov 2026, 16:44 UTC.