FKIE_CVE-2026-46195

Vulnerability from fkie_nvd - Published: 2026-05-28 10:16 - Updated: 2026-06-19 13:16
Severity
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: smb: client: validate dacloffset before building DACL pointers parse_sec_desc(), build_sec_desc(), and the chown path in id_mode_to_cifs_acl() all add the server-supplied dacloffset to pntsd before proving a DACL header fits inside the returned security descriptor. On 32-bit builds a malicious server can return dacloffset near U32_MAX, wrap the derived DACL pointer below end_of_acl, and then slip past the later pointer-based bounds checks. build_sec_desc() and id_mode_to_cifs_acl() can then dereference DACL fields from the wrapped pointer in the chmod/chown rewrite paths. Validate dacloffset numerically before building any DACL pointer and reuse the same helper at the three DACL entry points.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3b1ddba19e77ee35241cd27f16dc3e8d14e08db7Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5de2665e913a10ad70aaeecf736b97276e83d995
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/8bd07e417b6bda67e317920584e48cb6ee442a8aPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ba7f71b6161c0943dafc367565e5843d16b7d505Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c688f3ed73d31943334ad2139cb02ec49664322aPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f98b48151cc502ada59d9778f0112d21f2586ca3Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f9dc3be8f403c1216df73e57221f44b045e7ee0b
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel 7.1
linux linux_kernel 7.1
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/client/cifsacl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5de2665e913a10ad70aaeecf736b97276e83d995",
              "status": "affected",
              "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
              "versionType": "git"
            },
            {
              "lessThan": "f9dc3be8f403c1216df73e57221f44b045e7ee0b",
              "status": "affected",
              "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
              "versionType": "git"
            },
            {
              "lessThan": "ba7f71b6161c0943dafc367565e5843d16b7d505",
              "status": "affected",
              "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
              "versionType": "git"
            },
            {
              "lessThan": "3b1ddba19e77ee35241cd27f16dc3e8d14e08db7",
              "status": "affected",
              "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
              "versionType": "git"
            },
            {
              "lessThan": "c688f3ed73d31943334ad2139cb02ec49664322a",
              "status": "affected",
              "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
              "versionType": "git"
            },
            {
              "lessThan": "8bd07e417b6bda67e317920584e48cb6ee442a8a",
              "status": "affected",
              "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
              "versionType": "git"
            },
            {
              "lessThan": "f98b48151cc502ada59d9778f0112d21f2586ca3",
              "status": "affected",
              "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/client/cifsacl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.12"
            },
            {
              "lessThan": "5.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.210",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.176",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.140",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.88",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.30",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "806BFCDD-40F7-4D92-8A27-BFFEF6F38F7B",
              "versionEndExcluding": "6.6.140",
              "versionStartIncluding": "5.12",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "5AFBE0EC-CCDF-4207-AE92-ABF958125CA4",
              "versionEndExcluding": "6.12.88",
              "versionStartIncluding": "6.7",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "BF39AE08-AE6D-4410-8FBE-76F6BF5BF55B",
              "versionEndExcluding": "6.18.30",
              "versionStartIncluding": "6.13",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "D0893CA7-9AE6-4DFE-AC75-48967D73AD8E",
              "versionEndExcluding": "7.0.7",
              "versionStartIncluding": "6.19",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*",
              "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: validate dacloffset before building DACL pointers\n\nparse_sec_desc(), build_sec_desc(), and the chown path in\nid_mode_to_cifs_acl() all add the server-supplied dacloffset to pntsd\nbefore proving a DACL header fits inside the returned security\ndescriptor.\n\nOn 32-bit builds a malicious server can return dacloffset near\nU32_MAX, wrap the derived DACL pointer below end_of_acl, and then slip\npast the later pointer-based bounds checks. build_sec_desc() and\nid_mode_to_cifs_acl() can then dereference DACL fields from the wrapped\npointer in the chmod/chown rewrite paths.\n\nValidate dacloffset numerically before building any DACL pointer and\nreuse the same helper at the three DACL entry points."
    }
  ],
  "id": "CVE-2026-46195",
  "lastModified": "2026-06-19T13:16:35.223",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-05-28T10:16:35.147",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/3b1ddba19e77ee35241cd27f16dc3e8d14e08db7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5de2665e913a10ad70aaeecf736b97276e83d995"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/8bd07e417b6bda67e317920584e48cb6ee442a8a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/ba7f71b6161c0943dafc367565e5843d16b7d505"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/c688f3ed73d31943334ad2139cb02ec49664322a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/f98b48151cc502ada59d9778f0112d21f2586ca3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f9dc3be8f403c1216df73e57221f44b045e7ee0b"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


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