{
  "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-2026-31709",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-31709",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-05-01T13:56:06.522Z",
    "updatedAt": "2026-10-19T19:06:06.980Z",
    "importedAt": "2026-10-24T01:58:02.025Z",
    "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": "smb: client: validate the whole DACL before rewriting it in cifsacl",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: validate the whole DACL before rewriting it in cifsacl\n\nbuild_sec_desc() and id_mode_to_cifs_acl() derive a DACL pointer from a\nserver-supplied dacloffset and then use the incoming ACL to rebuild the\nchmod/chown security descriptor.\n\nThe original fix only checked that the struct smb_acl header fits before\nreading dacl_ptr->size or dacl_ptr->num_aces.  That avoids the immediate\nheader-field OOB read, but the rewrite helpers still walk ACEs based on\npdacl->num_aces with no structural validation of the incoming DACL body.\n\nA malicious server can return a truncated DACL that still contains a\nheader, claims one or more ACEs, and then drive\nreplace_sids_and_copy_aces() or set_chmod_dacl() past the validated\nextent while they compare or copy attacker-controlled ACEs.\n\nFactor the DACL structural checks into validate_dacl(), extend them to\nvalidate each ACE against the DACL bounds, and use the shared validator\nbefore the chmod/chown rebuild paths.  parse_dacl() reuses the same\nvalidator so the read-side parser and write-side rewrite paths agree on\nwhat constitutes a well-formed incoming DACL.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b8603d9ae6c9087662b098619996bc4a8064319d"
            },
            {
              "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c2abdebf72000a64603ced84d36ccbd164f11391"
            },
            {
              "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "8e47d297e7cf9a6029a0d38e7b22faba7d7aaf12"
            },
            {
              "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "d92f3f0b22414e7515696a02224d0af55e3004a3"
            },
            {
              "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "ff0ca46b13b9ef6edbcd238a3b6caacfef8ba0e5"
            },
            {
              "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b78db9bddc84136f6a0bb49e8883cf200dfb87a8"
            },
            {
              "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "0a8cf165566ba55a39fd0f4de172119dd646d39a"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "5.12",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "5.12"
            },
            {
              "version": "5.15.210",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.1.176",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.6.140",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.86",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.35",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.0.2",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.0.*"
            },
            {
              "version": "7.1",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}