{
  "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-2026-64298",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-64298",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-07-25T08:49:35.101Z",
    "updatedAt": "2026-10-19T20:38:22.558Z",
    "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": "NFSv4: include MAY_WRITE in open permission mask for O_TRUNC",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSv4: include MAY_WRITE in open permission mask for O_TRUNC\n\nPOSIX requires write permission to truncate a file, so an open() that\nspecifies O_TRUNC must be authorized for write access regardless of the\nO_ACCMODE access mode.\n\nnfs_open_permission_mask() builds the access mask passed to\nnfs_may_open(), which is the local authorization gate for OPENs the\nclient serves itself from a cached write delegation via the\ncan_open_delegated() path in nfs4_try_open_cached().  The mask is\nderived from O_ACCMODE alone, so an open(O_RDONLY | O_TRUNC) against a\nfile the caller cannot write requests only MAY_READ and passes the\nlocal check.  The OPEN is then satisfied locally and the truncation is\nissued to the server as a SETATTR(size=0) over the delegation stateid,\nwhich the server accepts under standard write-delegation semantics.\nPOSIX requires that this open fail with EACCES.\n\nInclude MAY_WRITE in the mask whenever O_TRUNC is set so the local\ncheck matches the access the server would have enforced.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "af22f94ae02ab9dd4fd7fe628c8434a59cc293be",
              "status": "affected",
              "versionType": "git",
              "lessThan": "4817c8974315b666e895b7d1bb83cd3664c323b1"
            },
            {
              "version": "af22f94ae02ab9dd4fd7fe628c8434a59cc293be",
              "status": "affected",
              "versionType": "git",
              "lessThan": "cb148a2762d644bff1894728e8835a9a4b84f9ea"
            },
            {
              "version": "af22f94ae02ab9dd4fd7fe628c8434a59cc293be",
              "status": "affected",
              "versionType": "git",
              "lessThan": "30fdf4df6c3c00efec947e4ddf97f0fdd4473628"
            },
            {
              "version": "af22f94ae02ab9dd4fd7fe628c8434a59cc293be",
              "status": "affected",
              "versionType": "git",
              "lessThan": "22c1fd1355ad4ca27aa7f0fa02719122dd92d9de"
            },
            {
              "version": "af22f94ae02ab9dd4fd7fe628c8434a59cc293be",
              "status": "affected",
              "versionType": "git",
              "lessThan": "6bd7d0a06b53c4e797e1a9cea0d2d41aa1b26230"
            },
            {
              "version": "af22f94ae02ab9dd4fd7fe628c8434a59cc293be",
              "status": "affected",
              "versionType": "git",
              "lessThan": "a937e92c1d00534b5c2e3e9f4381b7e988180797"
            },
            {
              "version": "af22f94ae02ab9dd4fd7fe628c8434a59cc293be",
              "status": "affected",
              "versionType": "git",
              "lessThan": "e36501b7d4abdcd6d69a7cb901b2f286b7a3d041"
            },
            {
              "version": "af22f94ae02ab9dd4fd7fe628c8434a59cc293be",
              "status": "affected",
              "versionType": "git",
              "lessThan": "5140f099ecd8a2f2808b7f7b720ee1bad8468974"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "2.6.24",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "2.6.24"
            },
            {
              "version": "5.10.261",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.212",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.1.178",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.6.145",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.96",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.39",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.1.4",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "version": "7.2",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}