FKIE_CVE-2026-31717

Vulnerability from fkie_nvd - Published: 2026-05-01 14:16 - Updated: 2026-06-17 10:34
Severity
8.8 (High) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate owner of durable handle on reconnect Currently, ksmbd does not verify if the user attempting to reconnect to a durable handle is the same user who originally opened the file. This allows any authenticated user to hijack an orphaned durable handle by predicting or brute-forcing the persistent ID. According to MS-SMB2, the server MUST verify that the SecurityContext of the reconnect request matches the SecurityContext associated with the existing open. Add a durable_owner structure to ksmbd_file to store the original opener's UID, GID, and account name. and catpure the owner information when a file handle becomes orphaned. and implementing ksmbd_vfs_compare_durable_owner() to validate the identity of the requester during SMB2_CREATE (DHnC).
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/00ce8d6789dae72d042a4522264964c72891ca37Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/49110a8ce654bbe56bef7c5e44cce31f4b102b8aPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/712cdf917e77a6444ce3836874829d770db20ee6
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c7f0f0d01c88bdcb8b1694d7d321670013f7ed7d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c908c853f304a4969b5aa10eba0b50350cc65b80Patch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel 7.1
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/mgmt/user_session.c",
            "fs/smb/server/oplock.c",
            "fs/smb/server/oplock.h",
            "fs/smb/server/smb2pdu.c",
            "fs/smb/server/vfs_cache.c",
            "fs/smb/server/vfs_cache.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "712cdf917e77a6444ce3836874829d770db20ee6",
              "status": "affected",
              "version": "8df4bcdb0a4232192b2445256c39b787d58ef14d",
              "versionType": "git"
            },
            {
              "lessThan": "c7f0f0d01c88bdcb8b1694d7d321670013f7ed7d",
              "status": "affected",
              "version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
              "versionType": "git"
            },
            {
              "lessThan": "c908c853f304a4969b5aa10eba0b50350cc65b80",
              "status": "affected",
              "version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
              "versionType": "git"
            },
            {
              "lessThan": "49110a8ce654bbe56bef7c5e44cce31f4b102b8a",
              "status": "affected",
              "version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
              "versionType": "git"
            },
            {
              "lessThan": "6.6.142",
              "status": "affected",
              "version": "6.6.32",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/mgmt/user_session.c",
            "fs/smb/server/oplock.c",
            "fs/smb/server/oplock.h",
            "fs/smb/server/smb2pdu.c",
            "fs/smb/server/vfs_cache.c",
            "fs/smb/server/vfs_cache.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.9"
            },
            {
              "lessThan": "6.9",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.142",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.92",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.25",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.2",
              "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": "2C15E547-F33F-4337-A576-685C65C6D439",
              "versionEndExcluding": "6.7",
              "versionStartIncluding": "6.6.32",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "FB3AD8C5-FEB3-4B8C-A314-EFD501361AE9",
              "versionEndExcluding": "6.18.25",
              "versionStartIncluding": "6.9",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "1BD58F1E-7C20-4C0D-92A2-FAC5CBFBE8A8",
              "versionEndExcluding": "7.0.2",
              "versionStartIncluding": "6.19",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: validate owner of durable handle on reconnect\n\nCurrently, ksmbd does not verify if the user attempting to reconnect\nto a durable handle is the same user who originally opened the file.\nThis allows any authenticated user to hijack an orphaned durable handle\nby predicting or brute-forcing the persistent ID.\n\nAccording to MS-SMB2, the server MUST verify that the SecurityContext\nof the reconnect request matches the SecurityContext associated with\nthe existing open.\nAdd a durable_owner structure to ksmbd_file to store the original opener\u0027s\nUID, GID, and account name. and catpure the owner information when a file\nhandle becomes orphaned. and implementing ksmbd_vfs_compare_durable_owner()\nto validate the identity of the requester during SMB2_CREATE (DHnC)."
    }
  ],
  "id": "CVE-2026-31717",
  "lastModified": "2026-06-17T10:34:18.033",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-05-01T14:16:21.860",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/00ce8d6789dae72d042a4522264964c72891ca37"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/49110a8ce654bbe56bef7c5e44cce31f4b102b8a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/712cdf917e77a6444ce3836874829d770db20ee6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c7f0f0d01c88bdcb8b1694d7d321670013f7ed7d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/c908c853f304a4969b5aa10eba0b50350cc65b80"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


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