{
  "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-2021-47217",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-47217",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2024-04-10T19:01:56.419Z",
    "updatedAt": "2026-05-11T13:50:14.845Z",
    "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": "x86/hyperv: Fix NULL deref in set_hv_tscchange_cb() if Hyper-V setup fails",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/hyperv: Fix NULL deref in set_hv_tscchange_cb() if Hyper-V setup fails\n\nCheck for a valid hv_vp_index array prior to derefencing hv_vp_index when\nsetting Hyper-V's TSC change callback.  If Hyper-V setup failed in\nhyperv_init(), the kernel will still report that it's running under\nHyper-V, but will have silently disabled nearly all functionality.\n\n  BUG: kernel NULL pointer dereference, address: 0000000000000010\n  #PF: supervisor read access in kernel mode\n  #PF: error_code(0x0000) - not-present page\n  PGD 0 P4D 0\n  Oops: 0000 [#1] SMP\n  CPU: 4 PID: 1 Comm: swapper/0 Not tainted 5.15.0-rc2+ #75\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\n  RIP: 0010:set_hv_tscchange_cb+0x15/0xa0\n  Code: <8b> 04 82 8b 15 12 17 85 01 48 c1 e0 20 48 0d ee 00 01 00 f6 c6 08\n  ...\n  Call Trace:\n   kvm_arch_init+0x17c/0x280\n   kvm_init+0x31/0x330\n   vmx_init+0xba/0x13a\n   do_one_initcall+0x41/0x1c0\n   kernel_init_freeable+0x1f2/0x23b\n   kernel_init+0x16/0x120\n   ret_from_fork+0x22/0x30",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "93286261de1b46339aa27cd4c639b21778f6cade",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b20ec58f8a6f4fef32cc71480ddf824584e24743"
            },
            {
              "version": "93286261de1b46339aa27cd4c639b21778f6cade",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b0e44dfb4e4c699cca33ede431b8d127e6e8d661"
            },
            {
              "version": "93286261de1b46339aa27cd4c639b21778f6cade",
              "status": "affected",
              "versionType": "git",
              "lessThan": "9c177eee116cf888276d3748cb176e72562cfd5c"
            },
            {
              "version": "93286261de1b46339aa27cd4c639b21778f6cade",
              "status": "affected",
              "versionType": "git",
              "lessThan": "8823ea27fff6084bbb4bc71d15378fae0220b1d8"
            },
            {
              "version": "93286261de1b46339aa27cd4c639b21778f6cade",
              "status": "affected",
              "versionType": "git",
              "lessThan": "daf972118c517b91f74ff1731417feb4270625a4"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "4.16",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "4.16"
            },
            {
              "version": "4.19.218",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.19.*"
            },
            {
              "version": "5.4.162",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.4.*"
            },
            {
              "version": "5.10.82",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.5",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "5.16",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}