Vulnerability-Lookup

FKIE_CVE-2026-31717

Vulnerability from fkie_nvd - Published: 2026-05-01 14:16 - Updated: 2026-05-06 21:08

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

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/00ce8d6789dae72d042a4522264964c72891ca37	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/49110a8ce654bbe56bef7c5e44cce31f4b102b8a	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/c908c853f304a4969b5aa10eba0b50350cc65b80	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	7.1

JSON

To clipboard

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
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              "versionEndExcluding": "6.7",
              "versionStartIncluding": "6.6.32",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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              "vulnerable": true
            },
            {
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              "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390",
              "vulnerable": true
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  "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": "2026-05-06T21:08:51.140",
  "metrics": {
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        "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",
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        "impactScore": 5.9,
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        "type": "Secondary"
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  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2026-31717 (GCVE-0-2026-31717)

Vulnerability from cvelistv5 – Published: 2026-05-01 13:56 – Updated: 2026-05-11 22:14

Title

ksmbd: validate owner of durable handle on reconnect

Summary

Severity ?

8.8 (High)


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

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/00ce8d6789dae72d0…
https://git.kernel.org/stable/c/c908c853f304a4969…
https://git.kernel.org/stable/c/49110a8ce654bbe56…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: c8efcc786146a951091588e5fa7e3c754850cb3c , < 00ce8d6789dae72d042a4522264964c72891ca37 (git) Affected: c8efcc786146a951091588e5fa7e3c754850cb3c , < c908c853f304a4969b5aa10eba0b50350cc65b80 (git) Affected: c8efcc786146a951091588e5fa7e3c754850cb3c , < 49110a8ce654bbe56bef7c5e44cce31f4b102b8a (git) Affected: 8df4bcdb0a4232192b2445256c39b787d58ef14d (git)
Linux	Linux	Affected: 6.9 Unaffected: 0 , < 6.9 (semver) Unaffected: 6.18.25 , ≤ 6.18.* (semver) Unaffected: 7.0.2 , ≤ 7.0.* (semver) Unaffected: 7.1-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
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      "affected": [
        {
          "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"
          ],
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              "status": "affected",
              "version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
              "versionType": "git"
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            {
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        },
        {
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          "programFiles": [
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            "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"
          ],
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              "versionType": "semver"
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              "status": "unaffected",
              "version": "6.18.25",
              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "7.0.2",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1-rc1",
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            }
          ]
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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.

Action not permitted

FKIE_CVE-2026-31717

CVE-2026-31717 (GCVE-0-2026-31717)

Tags

Sightings

Nomenclature