cbcvebase.
CVE-2026-23401
published 2026-04-01

CVE-2026-23401: In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Drop/zap existing present SPTE even when creating an MMIO SPTE When…

PriorityP423medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.18%
8.2th percentile
In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Drop/zap existing present SPTE even when creating an MMIO SPTE When installing an emulated MMIO SPTE, do so *after* dropping/zapping the existing SPTE (if it's shadow-present). While commit a54aa15c6bda3 was right about it being impossible to convert a shadow-present SPTE to an MMIO SPTE due to a _guest_ write, it failed to account for writes to guest memory that are outside the scope of KVM. E.g. if host userspace modifies a shadowed gPTE to switch from a memslot to emulted MMIO and then the guest hits a relevant page fault, KVM will install the MMIO SPTE without first zapping the shadow-present SPTE. ------------[ cut here ]------------ is_shadow_present_pte(*sptep) WARNING: arch/x86/kvm/mmu/mmu.c:484 at mark_mmio_spte+0xb2/0xc0 [kvm], CPU#0: vmx_ept_stale_r/4292 Modules linked in: kvm_intel kvm irqbypass CPU: 0 UID: 1000 PID: 4292 Comm: vmx_ept_stale_r Not tainted 7.0.0-rc2-eafebd2d2ab0-sink-vm #319 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:mark_mmio_spte+0xb2/0xc0 [kvm] Call Trace: mmu_set_spte+0x237/0x440 [kvm] ept_page_fault+0x535/0x7f0 [kvm] kvm_mmu_do_page_fault+0xee/0x1f0 [kvm] kvm_mmu_page_fault+0x8d/0x620 [kvm] vmx_handle_exit+0x18c/0x5a0 [kvm_intel] kvm_arch_vcpu_ioctl_run+0xc55/0x1c20 [kvm] kvm_vcpu_ioctl+0x2d5/0x980 [kvm] __x64_sys_ioctl+0x8a/0xd0 do_syscall_64+0xb5/0x730 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x47fa3f ---[ end trace 0000000000000000 ]---

Affected

61 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.19.11-1 (sid)linux 6.19.11-1 (sid)
linuxlinux
linuxlinux>= a54aa15c6bda3ca7e2f9e040ba968a1da303e24f < 20656cd1f243d3a154aac5dd1b823110b6906fe120656cd1f243d3a154aac5dd1b823110b6906fe1
linuxlinux>= a54aa15c6bda3ca7e2f9e040ba968a1da303e24f < ed5909992f344a7d3f4024261e9f751d9618a27ded5909992f344a7d3f4024261e9f751d9618a27d
linuxlinux>= a54aa15c6bda3ca7e2f9e040ba968a1da303e24f < fd28c5618699180cd69619801e9ae6a5266c0a22fd28c5618699180cd69619801e9ae6a5266c0a22
linuxlinux>= a54aa15c6bda3ca7e2f9e040ba968a1da303e24f < 459158151a158a6703b49f3c9de0e536d8bd553f459158151a158a6703b49f3c9de0e536d8bd553f
linuxlinux>= a54aa15c6bda3ca7e2f9e040ba968a1da303e24f < 695320de6eadb75aaed8be1787c4ce4c189e4c7b695320de6eadb75aaed8be1787c4ce4c189e4c7b
linuxlinux>= a54aa15c6bda3ca7e2f9e040ba968a1da303e24f < bce7fe59d43531623f3e43779127bfb33804925dbce7fe59d43531623f3e43779127bfb33804925d
linuxlinux>= a54aa15c6bda3ca7e2f9e040ba968a1da303e24f < aad885e774966e97b675dfe928da164214a71605aad885e774966e97b675dfe928da164214a71605
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 5.13.1 < 5.15.2035.15.203
linuxlinux_kernel>= 5.16 < 6.1.1686.1.168
linuxlinux_kernel>= 6.13 < 6.18.216.18.21
linuxlinux_kernel>= 6.19 < 6.19.116.19.11
linuxlinux_kernel>= 6.2 < 6.6.1316.6.131
linuxlinux_kernel>= 6.7 < 6.12.806.12.80
msrcazl3_kernel_6.6.130.1-3_on_azure_linux_3.0
ubuntulinux

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
vendor_msrc8.4HIGH
vendor_redhat8.1HIGH
vendor_ubuntu7.1HIGH
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