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HighFix available

ksmbd: validate owner of durable handle on reconnect

Type: advisorySources: OSV

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).

Products
Kernel
Affected versions
Not specified
Fixed versions
6.12.92, 6.18.25, 6.6.142, 7.0.2
CVEs
CVE-2026-31717
Confirmed fixed CVEs
Not specified
Updated in this feed
6 Nov 2026, 01:57 UTC · Revision 1

Source evidence

ksmbd: validate owner of durable handle on reconnect

core-osv · Original source

Published 1 May 2026, 13:56 UTC

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).

osv:CVE-2026-31717

Kernel

Fixed versions: 6.6.142, 6.12.92, 6.18.25, 7.0.2

Complete source record
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  "url": "https://osv.dev/vulnerability/CVE-2026-31717",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ksmbd: validate owner of durable handle on reconnect",
    "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).",
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      ],
      "modified": "2026-10-28T02:30:46.062577936Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/00ce8d6789dae72d042a4522264964c72891ca37",
        "https://git.kernel.org/stable/c/49110a8ce654bbe56bef7c5e44cce31f4b102b8a",
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        "https://nvd.nist.gov/vuln/detail/CVE-2026-31717",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31717.json"
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    },
    "related_cves": [
      {
        "value": "CVE-2026-31717",
        "evidence": "/id"
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    "severity_evidence": "/severity/0/score"
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  "source_id": "core-osv",
  "document_id": 514063,
  "published_at": "2026-05-01T13:56:12.012+00:00"
}