{
  "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-2025-40190",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-40190",
    "idYear": 2025,
    "status": "PUBLISHED",
    "publishedAt": "2025-11-12T21:56:30.914Z",
    "updatedAt": "2026-08-05T12:08:26.693Z",
    "importedAt": "2026-10-24T01:57:34.152Z",
    "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: guard against EA inode refcount underflow in xattr update",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: guard against EA inode refcount underflow in xattr update\n\nsyzkaller found a path where ext4_xattr_inode_update_ref() reads an EA\ninode refcount that is already <= 0 and then applies ref_change (often\n-1). That lets the refcount underflow and we proceed with a bogus value,\ntriggering errors like:\n\n  EXT4-fs error: EA inode <n> ref underflow: ref_count=-1 ref_change=-1\n  EXT4-fs warning: ea_inode dec ref err=-117\n\nMake the invariant explicit: if the current refcount is non-positive,\ntreat this as on-disk corruption, emit ext4_error_inode(), and fail the\noperation with -EFSCORRUPTED instead of updating the refcount. Delete the\nWARN_ONCE() as negative refcounts are now impossible; keep error reporting\nin ext4_error_inode().\n\nThis prevents the underflow and the follow-on orphan/cleanup churn.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "status": "affected",
              "versionType": "git",
              "lessThan": "ea39e712c2f5ae148ee5515798ae03523673e002"
            },
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "status": "affected",
              "versionType": "git",
              "lessThan": "1cfb3e4ddbdc8e02e637b8852540bd4718bf4814"
            },
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "status": "affected",
              "versionType": "git",
              "lessThan": "505e69f76ac497e788f4ea0267826ec7266b40c8"
            },
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "status": "affected",
              "versionType": "git",
              "lessThan": "3d6269028246f4484bfed403c947a114bb583631"
            },
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "status": "affected",
              "versionType": "git",
              "lessThan": "79ea7f3e11effe1bd9e753172981d9029133a278"
            },
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "status": "affected",
              "versionType": "git",
              "lessThan": "6b879c4c6bbaab03c0ad2a983953bd1410bb165e"
            },
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "status": "affected",
              "versionType": "git",
              "lessThan": "440b003f449a4ff2a00b08c8eab9ba5cd28f3943"
            },
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "status": "affected",
              "versionType": "git",
              "lessThan": "57295e835408d8d425bef58da5253465db3d6888"
            },
            {
              "version": "0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "5.4.301"
            },
            {
              "version": "0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "5.10.246"
            },
            {
              "version": "0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "5.15.195"
            },
            {
              "version": "0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.1.157"
            },
            {
              "version": "0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.6.113"
            },
            {
              "version": "0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.12.54"
            },
            {
              "version": "0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.17.4"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "5.4.301",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.4.*"
            },
            {
              "version": "5.10.246",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.195",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.1.157",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.6.113",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.54",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.17.4",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.17.*"
            },
            {
              "version": "6.18",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}