CVE-2026-23401

MEDIUM EPSS 6.2%
Published Apr 1, 20262mo ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Apr 1, 2026 2mo ago
Last Modified Jun 17, 2026 1w ago

Description

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: <TASK> 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 </TASK> ---[ end trace 0000000000000000 ]---

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
6.2% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Affected Products 14

VendorProductVersionRange
linuxlinux_kernel*≥5.13.1  –  <5.15.203
linuxlinux_kernel*≥5.16  –  <6.1.168
linuxlinux_kernel*≥6.2  –  <6.6.131
linuxlinux_kernel*≥6.7  –  <6.12.80
linuxlinux_kernel*≥6.13  –  <6.18.21
linuxlinux_kernel*≥6.19  –  <6.19.11
linuxlinux_kernel5.13any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any

References 7

  • git.kernel.org https://git.kernel.org/stable/c/20656cd1f243d3a154aac5dd1b823110b6906fe1
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/459158151a158a6703b49f3c9de0e536d8bd553f
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/695320de6eadb75aaed8be1787c4ce4c189e4c7b
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/aad885e774966e97b675dfe928da164214a71605
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/bce7fe59d43531623f3e43779127bfb33804925d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ed5909992f344a7d3f4024261e9f751d9618a27d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/fd28c5618699180cd69619801e9ae6a5266c0a22
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/20656cd1f243d3a154aac5dd1b823110b6906fe1
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/459158151a158a6703b49f3c9de0e536d8bd553f
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/695320de6eadb75aaed8be1787c4ce4c189e4c7b
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/aad885e774966e97b675dfe928da164214a71605
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/bce7fe59d43531623f3e43779127bfb33804925d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ed5909992f344a7d3f4024261e9f751d9618a27d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/fd28c5618699180cd69619801e9ae6a5266c0a22
    Patch