{
  "cveId": "CVE-2026-89908",
  "url": "https://patchblox.com/security/cve/CVE-2026-89908",
  "summary": "CVE-2026-89908 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-89908, released September 23, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "LoongArch: KVM: Preserve memslot arch flags on KVM_MR_FLAGS_ONLY",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  LoongArch: KVM: Preserve memslot arch flags on KVM_MR_FLAGS_ONLY  kvm_arch_prepare_memory_region() computes new-\u003Earch.flags, i.e. whether a memslot is KVM_MEM_HUGEPAGE_CAPABLE or KVM_MEM_HUGEPAGE_INCAPABLE, only for KVM_MR_CREATE and KVM_MR_MOVE, and returns early for every other change. But the generic code allocates a zeroed memslot for every change and never copies old-\u003Earch, so after a KVM_MR_FLAGS_ONLY update, e.g. toggling KVM_MEM_LOG_DIRTY_PAGES for live migration, the active memslot has arch.flags == 0.  With both flags clear, fault_supports_huge_mapping() falls through to the alignment check on the HVA range alone, which no longer verifies that the GPA and HVA have the same offset within a PMD. A memslot that was marked KVM_MEM_HUGEPAGE_INCAPABLE because of a GPA/HVA offset mismatch can then be mapped with PMD entries on read faults, and since kvm_map_page() aligns the gfn and the pfn independently, the guest ends up accessing the wrong host pages, exactly the \u0022d -\u003E f, e -\u003E g\u0022 case described in the comment above the check.  Carry the arch flags over from the old memslot for KVM_MR_FLAGS_ONLY, as the GPA, HVA and size are guaranteed to be unchanged for that case.",
  "published": "2026-09-16T11:16:59Z",
  "severity": "high",
  "cvss": 8.8,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
  "epss": 0.00175,
  "epssPercentile": 0.07046,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-89908",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.111-1",
      "fix": "DEBIAN-CVE-2026-89908",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-89908",
      "released": "2026-09-23T19:19:02Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.6-1",
      "fix": "DEBIAN-CVE-2026-89908",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-89908",
      "released": "2026-09-23T19:19:02Z"
    },
    {
      "platform": "linux",
      "product": "linux-6.12",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.12.111-1~deb12u1",
      "fix": "DEBIAN-CVE-2026-89908",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-89908",
      "released": "2026-09-23T19:19:02Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T00:53:09Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}