{
  "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-2026-74439",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-74439",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-08-15T05:59:36.655Z",
    "updatedAt": "2026-10-16T19:05:45.325Z",
    "importedAt": "2026-10-24T01:58:30.346Z",
    "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": "iommu/vt-d: Clear Present bit before tearing down scalable-mode context entry",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Clear Present bit before tearing down scalable-mode context entry\n\ndevice_pasid_table_teardown() zeroes the 128-bit scalable-mode context\nentry with context_clear_entry() while the Present bit is still set. This\ncreates a window where the hardware can fetch a torn entry, with some\nfields already zeroed while Present is still set, leading to unpredictable\nbehavior or spurious faults. The context-cache invalidation is issued only\nafter the entry has been zeroed, and intel_pasid_free_table() then frees\nthe PASID directory pages, so the IOMMU can keep walking a stale Present=1\nentry that points at freed memory.\n\nWhile x86 provides strong write ordering, the compiler may reorder the two\n64-bit writes to the entry, and the hardware fetch is not guaranteed to be\natomic with respect to multiple CPU writes.\n\nCommit c1e4f1dccbe9d (\"iommu/vt-d: Clear Present bit before tearing down\ncontext entry\") fixed this exact pattern in domain_context_clear_one() and\nthe copied-context path, but device_pasid_table_teardown() was not\nconverted.\n\nAlign it with the \"Guidance to Software for Invalidations\" in the VT-d\nspec, Section 6.5.3.3, using the same ownership handshake as the sibling\nfix: clear only the Present bit, flush it to the IOMMU, perform the\ncontext-cache invalidation, and only then zero the rest of the entry.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "81e921fd321614c2ad8ac333b041aae1da7a1c6d",
              "status": "affected",
              "versionType": "git",
              "lessThan": "e9e83bcfe37dc719182500dd823c03ab57d934f0"
            },
            {
              "version": "81e921fd321614c2ad8ac333b041aae1da7a1c6d",
              "status": "affected",
              "versionType": "git",
              "lessThan": "588718101e8449605f1c7e858fecb7cfa701cdab"
            },
            {
              "version": "81e921fd321614c2ad8ac333b041aae1da7a1c6d",
              "status": "affected",
              "versionType": "git",
              "lessThan": "7fd4077dc92b91b1b844333c0a06bb9e286db10a"
            },
            {
              "version": "81e921fd321614c2ad8ac333b041aae1da7a1c6d",
              "status": "affected",
              "versionType": "git",
              "lessThan": "f46452c3df7a8d8a5addc0926e76ef19ea7da0a0"
            },
            {
              "version": "333fe86968482ca701c609af590003bcea450e8f",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "6.8.2",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.9"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.9",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.9"
            },
            {
              "version": "6.12.97",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.40",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.1.5",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "version": "7.2",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}