Vulnerability-Lookup

FKIE_CVE-2026-64395

Vulnerability from fkie_nvd - Published: 2026-07-25 10:17 - Updated: 2026-09-04 14:47

Severity

7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Summary

In the Linux kernel, the following vulnerability has been resolved: ksmbd: require source read access for duplicate extents FSCTL_DUPLICATE_EXTENTS_TO_FILE passes the source file directly to vfs_clone_file_range() or vfs_copy_file_range() without checking the SMB access mask granted to the source handle. A handle opened with attribute access can consequently be used to copy file contents into an attacker-readable destination. Require FILE_READ_DATA on the source handle before either VFS operation, matching other ksmbd data-copy paths.

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/2d2ab6983620c2d60ce7db72133984ca3873b929	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/67bdad9cf01b25030e3bf00bbce6c309319d6663	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/a10942af27832c2761d020863a46e79bebe0567d	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/b0d4d5cb846a1ddb7aaab9adfb5986e4540e6e5f	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/cedff600f1642aa982178503552f0d007bc829c8	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/db231af842868268839f9f9619c68cb27830d8be	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/smb2pdu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "2d2ab6983620c2d60ce7db72133984ca3873b929",
              "status": "affected",
              "version": "eb817368f50c1cbe1bd07044124aad7db6330e3a",
              "versionType": "git"
            },
            {
              "lessThan": "67bdad9cf01b25030e3bf00bbce6c309319d6663",
              "status": "affected",
              "version": "eb817368f50c1cbe1bd07044124aad7db6330e3a",
              "versionType": "git"
            },
            {
              "lessThan": "b0d4d5cb846a1ddb7aaab9adfb5986e4540e6e5f",
              "status": "affected",
              "version": "eb817368f50c1cbe1bd07044124aad7db6330e3a",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "eb817368f50c1cbe1bd07044124aad7db6330e3a",
              "versionType": "git"
            },
            {
              "lessThan": "a10942af27832c2761d020863a46e79bebe0567d",
              "status": "affected",
              "version": "eb817368f50c1cbe1bd07044124aad7db6330e3a",
              "versionType": "git"
            },
            {
              "lessThan": "cedff600f1642aa982178503552f0d007bc829c8",
              "status": "affected",
              "version": "eb817368f50c1cbe1bd07044124aad7db6330e3a",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
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              "version": "5.15"
            },
            {
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
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            {
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      ]
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  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: require source read access for duplicate extents\n\nFSCTL_DUPLICATE_EXTENTS_TO_FILE passes the source file directly to\nvfs_clone_file_range() or vfs_copy_file_range() without checking the SMB\naccess mask granted to the source handle. A handle opened with attribute\naccess can consequently be used to copy file contents into an\nattacker-readable destination.\n\nRequire FILE_READ_DATA on the source handle before either VFS operation,\nmatching other ksmbd data-copy paths."
    }
  ],
  "id": "CVE-2026-64395",
  "lastModified": "2026-09-04T14:47:48.093",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-25T10:17:22.923",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
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      ],
      "url": "https://git.kernel.org/stable/c/2d2ab6983620c2d60ce7db72133984ca3873b929"
    },
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      "tags": [
        "Patch"
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    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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      "url": "https://git.kernel.org/stable/c/a10942af27832c2761d020863a46e79bebe0567d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/b0d4d5cb846a1ddb7aaab9adfb5986e4540e6e5f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/cedff600f1642aa982178503552f0d007bc829c8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/db231af842868268839f9f9619c68cb27830d8be"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2026-64395 (GCVE-0-2026-64395)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:50 – Updated: 2026-08-17 04:54

Title

ksmbd: require source read access for duplicate extents

Summary

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Assigner

Linux mitre root

References

6 references

URL	Tags
https://git.kernel.org/stable/c/2d2ab6983620c2d60…
https://git.kernel.org/stable/c/67bdad9cf01b25030…
https://git.kernel.org/stable/c/b0d4d5cb846a1ddb7…
https://git.kernel.org/stable/c/db231af8428682688…
https://git.kernel.org/stable/c/a10942af27832c276…
https://git.kernel.org/stable/c/cedff600f1642aa98…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: eb817368f50c1cbe1bd07044124aad7db6330e3a , < 2d2ab6983620c2d60ce7db72133984ca3873b929 (git) Affected: eb817368f50c1cbe1bd07044124aad7db6330e3a , < 67bdad9cf01b25030e3bf00bbce6c309319d6663 (git) Affected: eb817368f50c1cbe1bd07044124aad7db6330e3a , < b0d4d5cb846a1ddb7aaab9adfb5986e4540e6e5f (git) Affected: eb817368f50c1cbe1bd07044124aad7db6330e3a , < db231af842868268839f9f9619c68cb27830d8be (git) Affected: eb817368f50c1cbe1bd07044124aad7db6330e3a , < a10942af27832c2761d020863a46e79bebe0567d (git) Affected: eb817368f50c1cbe1bd07044124aad7db6330e3a , < cedff600f1642aa982178503552f0d007bc829c8 (git)
Linux	Linux	Affected: 5.15 Unaffected: 0 , < 5.15 (semver) Unaffected: 6.1.178 , ≤ 6.1.* (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.96 , ≤ 6.12.* (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/smb2pdu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "2d2ab6983620c2d60ce7db72133984ca3873b929",
              "status": "affected",
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              "versionType": "git"
            },
            {
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              "version": "eb817368f50c1cbe1bd07044124aad7db6330e3a",
              "versionType": "git"
            },
            {
              "lessThan": "b0d4d5cb846a1ddb7aaab9adfb5986e4540e6e5f",
              "status": "affected",
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              "versionType": "git"
            },
            {
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              "versionType": "git"
            },
            {
              "lessThan": "a10942af27832c2761d020863a46e79bebe0567d",
              "status": "affected",
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              "versionType": "git"
            },
            {
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              "status": "affected",
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              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "version": "5.15"
            },
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
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          "nodes": [
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              "cpeMatch": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.178",
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                },
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        }
      ],
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            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The vulnerable SMB2 IOCTL is remotely reachable through ksmbd over TCP, normally port 445.\nAC:L - The attacker controls both handles, offsets, and copy length; no race is required, and exploitation is reliable on common reflink-capable filesystems such as XFS and Btrfs.\nPR:N - In a reasonable guest-enabled writable-share deployment, an unauthenticated remote attacker can establish a guest session without credentials and obtain the required attribute-only source and writable destination handles.\nUI:N - After connecting to the share, the attacker can open both handles and issue the IOCTL without any victim action.\nS:U - The bypass discloses files governed by the same kernel and SMB server security authority and does not cross a virtualization or other security scope.\nC:H - Attacker-controlled offsets and lengths allow complete copying of otherwise unreadable files into an attacker-readable destination, causing total confidentiality loss for protected share contents.\nI:N - The source is not modified, and the destination must already be on a writable tree and opened with FILE_WRITE_DATA, so the flaw adds no unauthorized modification capability.\nA:N - The operation does not corrupt memory, crash the kernel, or inherently disrupt service; any destination writes are already authorized by the required handle permissions."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T04:54:49.007Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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        {
          "url": "https://git.kernel.org/stable/c/a10942af27832c2761d020863a46e79bebe0567d"
        },
        {
          "url": "https://git.kernel.org/stable/c/cedff600f1642aa982178503552f0d007bc829c8"
        }
      ],
      "title": "ksmbd: require source read access for duplicate extents",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64395",
    "datePublished": "2026-07-25T08:50:40.393Z",
    "dateReserved": "2026-07-19T15:36:31.785Z",
    "dateUpdated": "2026-08-17T04:54:49.007Z",
    "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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.