{
  "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-2026-68166",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-68166",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-08-10T11:59:34.576Z",
    "updatedAt": "2026-08-23T12:46:02.309Z",
    "importedAt": "2026-10-24T01:58:25.636Z",
    "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": "userfaultfd: prevent registration of special VMAs",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nuserfaultfd: prevent registration of special VMAs\n\nVova Tokarev says:\n\n  userfaultfd allows registration on shadow stack VMAs.  With userfaultfd\n  access, you can register on the shadow stack, discard a page ... and\n  inject a page with chosen return addresses via UFFDIO_COPY.\n\nUpdate vma_can_userfault() to reject VM_SHADOW_STACK.\n\nWhile on it, also reject VM_SPECIAL so that if a driver would implement\nvm_uffd_ops, it wouldn't be possible to register special VMAs with\nuserfaultfd.\n\nSince VM_SPECIAL includes VM_DONTEXPAND which is set but hugetlb, exclude\nhugetlb VMAs from the check for VM_SPECIAL.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "54007f818206dc27309ca423df4c87dd160a7208",
              "status": "affected",
              "versionType": "git",
              "lessThan": "d974b4b786214883bd8e56bda10b454c80fd6205"
            },
            {
              "version": "54007f818206dc27309ca423df4c87dd160a7208",
              "status": "affected",
              "versionType": "git",
              "lessThan": "495a28d5a100be1b232633f4c2dcc42ba10b3796"
            },
            {
              "version": "54007f818206dc27309ca423df4c87dd160a7208",
              "status": "affected",
              "versionType": "git",
              "lessThan": "165613191ad9d034bf17c00e3a142f9561597ec5"
            },
            {
              "version": "54007f818206dc27309ca423df4c87dd160a7208",
              "status": "affected",
              "versionType": "git",
              "lessThan": "0c26202b157f1efc3cd2f26f5c30f59b508a6a5d"
            },
            {
              "version": "54007f818206dc27309ca423df4c87dd160a7208",
              "status": "affected",
              "versionType": "git",
              "lessThan": "3c58f641e813c3c71039f8fd4d4e2a3aab713288"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.6",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.6"
            },
            {
              "version": "6.6.153",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.105",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.44",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.1.6",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "version": "7.2",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}