{
  "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-2026-89787",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-89787",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-09-16T08:48:24.403Z",
    "updatedAt": "2026-10-19T08:52:40.961Z",
    "importedAt": "2026-10-24T01:58:35.090Z",
    "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: check dir entry fits before reading the hash trailer in ext4_search_dir()",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: check dir entry fits before reading the hash trailer in ext4_search_dir()\n\nFor casefolded encrypted directories ext4 stores an 8-byte hash trailer\nafter the name (EXT4_DIRENT_HASHES()), at an offset derived from\nde->name_len.  On the sb_no_casefold_compat_fallback() path ext4_match()\nreads that trailer, but ext4_search_dir()'s by-hand pre-check only tests\nde->name + de->name_len <= dlimit, which proves the name fits, not the\nrounded trailer.  A crafted entry whose name ends at the block boundary\npasses the check while EXT4_DIRENT_HASHES(de) lands past the block end,\nso ext4_match() reads out of bounds on an ordinary lookup.  KASAN reports\nit as a use-after-free when the page after the directory block holds a\nfreed object:\n\n  BUG: KASAN: use-after-free in ext4_match (fs/ext4/namei.c:1435)\n  Read of size 4 at addr ffff888010458000 by task exploit\n  Call Trace:\n   ext4_match (fs/ext4/namei.c:1435)\n   ext4_search_dir (fs/ext4/namei.c:1470)\n   __ext4_find_entry (fs/ext4/namei.c:1268 fs/ext4/namei.c:1632)\n   ext4_lookup (fs/ext4/namei.c:1703 fs/ext4/namei.c:1769)\n   ...\n   filename_lookup (fs/namei.c:2842)\n   vfs_statx (fs/stat.c:353)\n   __do_sys_newfstatat (fs/stat.c:538)\n   do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n\nRequire, for hash-in-dirent directories, that the whole entry including\nthe rounded trailer fits before calling ext4_match().  This is the same\nbound ext4_check_dir_entry() already enforces via ext4_dir_rec_len(), so\nno well-formed entry is rejected.  The other caller, ext4_find_dest_de(),\nruns ext4_check_dir_entry() first and is unaffected.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500",
              "status": "affected",
              "versionType": "git",
              "lessThan": "4d20106c536b73c4a8a02652dc85e35898baebf7"
            },
            {
              "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500",
              "status": "affected",
              "versionType": "git",
              "lessThan": "61a395967de06edba58760e81907a272db749faa"
            },
            {
              "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500",
              "status": "affected",
              "versionType": "git",
              "lessThan": "e94676a08af6312aa72d8a981232b281f9bcfcf5"
            },
            {
              "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500",
              "status": "affected",
              "versionType": "git",
              "lessThan": "d8c184bec24b5a00ae96d704856d935eaded1685"
            },
            {
              "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500",
              "status": "affected",
              "versionType": "git",
              "lessThan": "3933884bc3102898b458c53fbd1ac52eb9cdb8a4"
            },
            {
              "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500",
              "status": "affected",
              "versionType": "git",
              "lessThan": "83663c0b739480c00cfe785675db87520ec484ed"
            },
            {
              "version": "471fbbea7ff7061b2d6474665cb5a2ceb4fd6500",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c7e6b863d298f56522d0d08554bbea7f142e6588"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "5.13",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "5.13"
            },
            {
              "version": "5.15.221",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.1.188",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.6.157",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.110",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.52",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.2.6",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "version": "7.3",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}