CVE-2026-23401
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- CVE-2026-23401
CVE Details
| Release Date: | 2026-04-01 | |
| Impact: | Important | What is this? |
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:
See more information about CVE-2026-23401 from MITRE CVE dictionary and NIST NVD
NOTE: The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 metrics
| Base Score: | 8.8 |
| Vector String: | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| Version: | 3.1 |
| Attack Vector: | Local |
| Attack Complexity: | Low |
| Privileges Required: | Low |
| User Interaction: | None |
| Scope: | Changed |
| Confidentiality Impact: | High |
| Integrity Impact: | High |
| Availability Impact: | High |
Errata information
| Platform | Errata | Release Date |
| Oracle Linux version 10 (kernel-uek) | ELSA-2026-50170 | 2026-03-26 |
| Oracle Linux version 10 (kernel-uek) | ELSA-2026-50232 | 2026-04-15 |
| Oracle Linux version 8 (kernel-uek) | ELSA-2026-50171 | 2026-03-26 |
| Oracle Linux version 9 (kernel-uek) | ELSA-2026-50170 | 2026-03-26 |
| Oracle Linux version 9 (kernel-uek) | ELSA-2026-50171 | 2026-03-26 |
| Oracle Linux version 9 (kernel-uek) | ELSA-2026-50232 | 2026-04-15 |
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