{
  "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-2026-63909",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-63909",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-07-19T14:55:15.060Z",
    "updatedAt": "2026-08-05T12:37:02.949Z",
    "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": "ksmbd: OOB read regression in smb_check_perm_dacl() ACE-walk loops",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: OOB read regression in smb_check_perm_dacl() ACE-walk loops\n\nCommit d07b26f39246 (\"ksmbd: require minimum ACE size in\nsmb_check_perm_dacl()\") introduced a transposed bounds check:\n\n    if (offsetof(struct smb_ace, sid) + aces_size < CIFS_SID_BASE_SIZE)\n\nSince offsetof(..sid) is 8 and CIFS_SID_BASE_SIZE is 8, this evaluates\nto `aces_size < 0`. Because `aces_size` is always non-negative, this\ncheck becomes dead code and never breaks the loop.\n\nWorse, that commit removed the old 4-byte guard, meaning the loop now\nreads `ace->size` (offset 2) even when `aces_size` is 0-3 bytes. This\nre-opens a 2-byte heap out-of-bounds (OOB) read past the pntsd allocation\nduring subsequent SMB2_CREATE operations.\n\nFix this by properly transposing the comparison to require at least\n16 bytes (8-byte offset + 8-byte SID base), matching the correct form\nused in smb_inherit_dacl().",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "282cbbb476b9f35793452bc461934af4c7eca169",
              "status": "affected",
              "versionType": "git",
              "lessThan": "5500ba1d410aed1eded3eb04a76b10cfb4409334"
            },
            {
              "version": "f20adc4ef7428bc485ee83fd1a592252fb87718b",
              "status": "affected",
              "versionType": "git",
              "lessThan": "f6324b4240cf0b26a84c33f68a1222d727ff4af2"
            },
            {
              "version": "325d4ac11f526cb8964cff14548ccf02d8c756d8",
              "status": "affected",
              "versionType": "git",
              "lessThan": "0fe08c5776a798f46df1fd74b331be26bdd644d6"
            },
            {
              "version": "95e5aa3c3261da8c95b27d7aecf8ee39b9f86a4c",
              "status": "affected",
              "versionType": "git",
              "lessThan": "d333af32e4451285e427f2d9c29de3a39f6f6d48"
            },
            {
              "version": "90089584b2e25c4510b7b987387b4405f0673ece",
              "status": "affected",
              "versionType": "git",
              "lessThan": "94215d55b09445993929f4fc966061d61de74929"
            },
            {
              "version": "151b1799861fde38087c08f613abc2843ef597b0",
              "status": "affected",
              "versionType": "git",
              "lessThan": "4f7c131d2bdd7cd64b96f60d10be5ea72253f520"
            },
            {
              "version": "d07b26f39246a82399661936dd0c853983cfade7",
              "status": "affected",
              "versionType": "git",
              "lessThan": "0e60dafe97eca61721f3db456f97d97a80c6c8ae"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "6.6.140",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.6.143"
            },
            {
              "version": "6.12.84",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.12.93"
            },
            {
              "version": "6.18.25",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.18.35"
            },
            {
              "version": "7.0.2",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "7.0.12"
            }
          ]
        }
      ]
    }
  }
}