{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.1.170-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.85-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.19.11-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "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:    \u003cTASK\u003e    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    \u003c/TASK\u003e   ---[ end trace 0000000000000000 ]---",
  "id": "DEBIAN-CVE-2026-23401",
  "modified": "2026-09-14T16:47:45.027708146Z",
  "published": "2026-04-01T09:16:15.260Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-23401"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-23401"
  ]
}