Vulnerability-Lookup

GHSA-RP7M-XQ2F-R4CG

Vulnerability from github – Published: 2026-05-28 12:30 – Updated: 2026-05-28 12:30

Details

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.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-46195"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-28T10:16:35Z",
    "severity": null
  },
  "details": "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": "GHSA-rp7m-xq2f-r4cg",
  "modified": "2026-05-28T12:30:32Z",
  "published": "2026-05-28T12:30:32Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46195"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3b1ddba19e77ee35241cd27f16dc3e8d14e08db7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8bd07e417b6bda67e317920584e48cb6ee442a8a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ba7f71b6161c0943dafc367565e5843d16b7d505"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c688f3ed73d31943334ad2139cb02ec49664322a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f98b48151cc502ada59d9778f0112d21f2586ca3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-46195 (GCVE-0-2026-46195)

Vulnerability from cvelistv5 – Published: 2026-05-28 09:36 – Updated: 2026-05-28 09:36

Title

smb: client: validate dacloffset before building DACL pointers

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.

Severity

No CVSS data available.

Assigner

Linux

References

5 references

URL	Tags
https://git.kernel.org/stable/c/ba7f71b6161c0943d…
https://git.kernel.org/stable/c/3b1ddba19e77ee352…
https://git.kernel.org/stable/c/c688f3ed73d319433…
https://git.kernel.org/stable/c/8bd07e417b6bda67e…
https://git.kernel.org/stable/c/f98b48151cc502ada…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 , < ba7f71b6161c0943dafc367565e5843d16b7d505 (git) Affected: bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 , < 3b1ddba19e77ee35241cd27f16dc3e8d14e08db7 (git) Affected: bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 , < c688f3ed73d31943334ad2139cb02ec49664322a (git) Affected: bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 , < 8bd07e417b6bda67e317920584e48cb6ee442a8a (git) Affected: bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 , < f98b48151cc502ada59d9778f0112d21f2586ca3 (git)
Linux	Linux	Affected: 5.12 Unaffected: 0 , < 5.12 (semver) Unaffected: 6.6.140 , ≤ 6.6.* (semver) Unaffected: 6.12.88 , ≤ 6.12.* (semver) Unaffected: 6.18.30 , ≤ 6.18.* (semver) Unaffected: 7.0.7 , ≤ 7.0.* (semver) Unaffected: 7.1-rc3 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "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": "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": "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-rc3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.140",
                  "versionStartIncluding": "5.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
                },
                {
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                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.7",
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                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionStartIncluding": "5.12",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-28T09:36:48.259Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/ba7f71b6161c0943dafc367565e5843d16b7d505"
        },
        {
          "url": "https://git.kernel.org/stable/c/3b1ddba19e77ee35241cd27f16dc3e8d14e08db7"
        },
        {
          "url": "https://git.kernel.org/stable/c/c688f3ed73d31943334ad2139cb02ec49664322a"
        },
        {
          "url": "https://git.kernel.org/stable/c/8bd07e417b6bda67e317920584e48cb6ee442a8a"
        },
        {
          "url": "https://git.kernel.org/stable/c/f98b48151cc502ada59d9778f0112d21f2586ca3"
        }
      ],
      "title": "smb: client: validate dacloffset before building DACL pointers",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-46195",
    "datePublished": "2026-05-28T09:36:48.259Z",
    "dateReserved": "2026-05-13T15:03:33.104Z",
    "dateUpdated": "2026-05-28T09:36:48.259Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

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GHSA-RP7M-XQ2F-R4CG

CVE-2026-46195 (GCVE-0-2026-46195)

Tags

Sightings

Nomenclature