{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2021-47450",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-47450",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2024-05-22T06:19:41.443Z",
    "updatedAt": "2026-08-05T08:47:53.018Z",
    "importedAt": "2026-10-24T01:56:36.661Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "KVM: arm64: Fix host stage-2 PGD refcount",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Fix host stage-2 PGD refcount\n\nThe KVM page-table library refcounts the pages of concatenated stage-2\nPGDs individually. However, when running KVM in protected mode, the\nhost's stage-2 PGD is currently managed by EL2 as a single high-order\ncompound page, which can cause the refcount of the tail pages to reach 0\nwhen they shouldn't, hence corrupting the page-table.\n\nFix this by introducing a new hyp_split_page() helper in the EL2 page\nallocator (matching the kernel's split_page() function), and make use of\nit from host_s2_zalloc_pages_exact().",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "1025c8c0c6accfcbdc8f52ca1940160f65cd87d6",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b372264c66ef78f2cab44e877fbd765ad6d24c39"
            },
            {
              "version": "1025c8c0c6accfcbdc8f52ca1940160f65cd87d6",
              "status": "affected",
              "versionType": "git",
              "lessThan": "1d58a17ef54599506d44c45ac95be27273a4d2b1"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "5.13",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "5.13"
            },
            {
              "version": "5.14.15",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.14.*"
            },
            {
              "version": "5.15",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}