{
  "cveId": "CVE-2021-47450",
  "url": "https://patchblox.com/security/cve/CVE-2021-47450",
  "summary": "CVE-2021-47450 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47450, released May 22, 2024. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  KVM: arm64: Fix host stage-2 PGD refcount  The K...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  KVM: arm64: Fix host stage-2 PGD refcount  The KVM page-table library refcounts the pages of concatenated stage-2 PGDs individually. However, when running KVM in protected mode, the host\u0027s stage-2 PGD is currently managed by EL2 as a single high-order compound page, which can cause the refcount of the tail pages to reach 0 when they shouldn\u0027t, hence corrupting the page-table.  Fix this by introducing a new hyp_split_page() helper in the EL2 page allocator (matching the kernel\u0027s split_page() function), and make use of it from host_s2_zalloc_pages_exact().",
  "published": "2024-05-22T07:15:10Z",
  "severity": "medium",
  "cvss": 5.5,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00208,
  "epssPercentile": 0.10973,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "5.15.3-1",
      "fix": "DEBIAN-CVE-2021-47450",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47450",
      "released": "2024-05-22T07:15:10Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "5.15.3-1",
      "fix": "DEBIAN-CVE-2021-47450",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47450",
      "released": "2024-05-22T07:15:10Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "5.15.3-1",
      "fix": "DEBIAN-CVE-2021-47450",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47450",
      "released": "2024-05-22T07:15:10Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}