{
  "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-2026-45858",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-45858",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-05-27T12:15:37.738Z",
    "updatedAt": "2026-05-30T10:41:40.719Z",
    "importedAt": "2026-10-24T01:58:14.884Z",
    "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": "ext4: don't zero the entire extent if EXT4_EXT_DATA_PARTIAL_VALID1",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: don't zero the entire extent if EXT4_EXT_DATA_PARTIAL_VALID1\n\nWhen allocating initialized blocks from a large unwritten extent, or\nwhen splitting an unwritten extent during end I/O and converting it to\ninitialized, there is currently a potential issue of stale data if the\nextent needs to be split in the middle.\n\n       0  A      B  N\n       [UUUUUUUUUUUU]    U: unwritten extent\n       [--DDDDDDDD--]    D: valid data\n          |<-  ->| ----> this range needs to be initialized\n\next4_split_extent() first try to split this extent at B with\nEXT4_EXT_DATA_ENTIRE_VALID1 and EXT4_EXT_MAY_ZEROOUT flag set, but\next4_split_extent_at() failed to split this extent due to temporary lack\nof space. It zeroout B to N and mark the entire extent from 0 to N\nas written.\n\n       0  A      B  N\n       [WWWWWWWWWWWW]    W: written extent\n       [SSDDDDDDDDZZ]    Z: zeroed, S: stale data\n\next4_split_extent() then try to split this extent at A with\nEXT4_EXT_DATA_VALID2 flag set. This time, it split successfully and left\na stale written extent from 0 to A.\n\n       0  A      B   N\n       [WW|WWWWWWWWWW]\n       [SS|DDDDDDDDZZ]\n\nFix this by pass EXT4_EXT_DATA_PARTIAL_VALID1 to ext4_split_extent_at()\nwhen splitting at B, don't convert the entire extent to written and left\nit as unwritten after zeroing out B to N. The remaining work is just\nlike the standard two-part split. ext4_split_extent() will pass the\nEXT4_EXT_DATA_VALID2 flag when it calls ext4_split_extent_at() for the\nsecond time, allowing it to properly handle the split. If the split is\nsuccessful, it will keep extent from 0 to A as unwritten.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "dee1f973ca341c266229faa5a1a5bb268bed3531",
              "status": "affected",
              "versionType": "git",
              "lessThan": "58ddae5d77b1db3a27b891c75a8fa120239ac092"
            },
            {
              "version": "dee1f973ca341c266229faa5a1a5bb268bed3531",
              "status": "affected",
              "versionType": "git",
              "lessThan": "d17857b4fb9ba5745b59be0ef38fd532991fccbf"
            },
            {
              "version": "dee1f973ca341c266229faa5a1a5bb268bed3531",
              "status": "affected",
              "versionType": "git",
              "lessThan": "d67c8ecf3d8fda9b8ef80e6f665d84b6d6ac9d88"
            },
            {
              "version": "dee1f973ca341c266229faa5a1a5bb268bed3531",
              "status": "affected",
              "versionType": "git",
              "lessThan": "7015fcf473796e1d2d876f241bd9e0c36f3d4eef"
            },
            {
              "version": "dee1f973ca341c266229faa5a1a5bb268bed3531",
              "status": "affected",
              "versionType": "git",
              "lessThan": "1bf6974822d1dba86cf11b5f05498581cf3488a2"
            },
            {
              "version": "814a7833df19e1de7447f870ae890adb12561627",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "4319fd00002630a761fa5559a086f11ed7623006",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "e28b27be06c5e6a5236c0c0b370ca0768ab086bb",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "3.2.33",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "3.3"
            },
            {
              "version": "3.4.16",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "3.5"
            },
            {
              "version": "3.6.4",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "3.7"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "3.7",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "3.7"
            },
            {
              "version": "6.6.130",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.75",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.14",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "6.19.4",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.19.*"
            },
            {
              "version": "7.0",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}