CVE-2026-23401

Advisory lineage Upstream: 0 Downstream: 15
Analyzed
Published: 01 Apr 2026, 08:36
Last modified:11 May 2026, 22:06

Vulnerability Summary

Overall Risk (default)
low
22/100
CVSS Score
5.5 MEDIUM
v3.1 (nvd)
EPSS Score
0.01% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

01 Apr 2026, 08:36
Published
Vulnerability first disclosed
11 May 2026, 22:06
Last Modified
Vulnerability information updated

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 Metrics

  • v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.01%• Percentile: 2%

Affected Systems

  • linux•linux

    ≥ a54aa15c6bda3ca7e2f9e040ba968a1da303e24f, < 20656cd1f243d3a154aac5dd1b823110b6906fe1 | ≥ a54aa15c6bda3ca7e2f9e040ba968a1da303e24f, < ed5909992f344a7d3f4024261e9f751d9618a27d | ≥ a54aa15c6bda3ca7e2f9e040ba968a1da303e24f, < fd28c5618699180cd69619801e9ae6a5266c0a22 | ≥ a54aa15c6bda3ca7e2f9e040ba968a1da303e24f, < 459158151a158a6703b49f3c9de0e536d8bd553f | ≥ a54aa15c6bda3ca7e2f9e040ba968a1da303e24f, < 695320de6eadb75aaed8be1787c4ce4c189e4c7b | ≥ a54aa15c6bda3ca7e2f9e040ba968a1da303e24f, < bce7fe59d43531623f3e43779127bfb33804925d | ≥ a54aa15c6bda3ca7e2f9e040ba968a1da303e24f, < aad885e774966e97b675dfe928da164214a71605 | 5.13

  • linux•linux_kernel

    ≥ 5.13.1, < 5.15.203 | ≥ 5.16, < 6.1.168 | ≥ 6.2, < 6.6.131 | ≥ 6.7, < 6.12.80 | ≥ 6.13, < 6.18.21 | ≥ 6.19, < 6.19.11 | 5.13 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6 | 7.0:rc7

References (7)