CVE-2026-68166

{
  "id": "CVE-2026-68166",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-08-10T13:20:03.110",
  "lastModified": "2026-11-06T17:19:20.417",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "mm/userfaultfd.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "54007f818206dc27309ca423df4c87dd160a7208",
              "lessThan": "d974b4b786214883bd8e56bda10b454c80fd6205",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "54007f818206dc27309ca423df4c87dd160a7208",
              "lessThan": "495a28d5a100be1b232633f4c2dcc42ba10b3796",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "54007f818206dc27309ca423df4c87dd160a7208",
              "lessThan": "165613191ad9d034bf17c00e3a142f9561597ec5",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "54007f818206dc27309ca423df4c87dd160a7208",
              "lessThan": "0c26202b157f1efc3cd2f26f5c30f59b508a6a5d",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "54007f818206dc27309ca423df4c87dd160a7208",
              "lessThan": "3c58f641e813c3c71039f8fd4d4e2a3aab713288",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "mm/userfaultfd.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.6",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.6",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.153",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.105",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.44",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.6",
              "lessThanOrEqual": "7.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-11-06T16:43:33.609914Z",
          "id": "CVE-2026-68166",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0c26202b157f1efc3cd2f26f5c30f59b508a6a5d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/165613191ad9d034bf17c00e3a142f9561597ec5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3c58f641e813c3c71039f8fd4d4e2a3aab713288",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/495a28d5a100be1b232633f4c2dcc42ba10b3796",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d974b4b786214883bd8e56bda10b454c80fd6205",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}