FKIE_CVE-2026-52911

Vulnerability from fkie_nvd - Published: 2026-06-21 08:16 - Updated: 2026-07-08 15:13
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: scope conn->binding slowpath to bound sessions only When the binding SESSION_SETUP sets conn->binding = true, the flag stays set after the call so that the global session lookup in ksmbd_session_lookup_all() can find the session, which was not added to conn->sessions. Because the flag is connection-wide, the global lookup path will also resolve any other session by id if asked. Tighten the global lookup so that the returned session must have this connection registered in its channel xarray (sess->ksmbd_chann_list). The channel entry is installed by the existing binding_session path in ntlm_authenticate()/krb5_authenticate() when a SESSION_SETUP completes successfully, so this condition is a strict equivalent of "this connection has been accepted as a channel of this session". Connections that have not bound to a given session cannot reach it via the global table. The existing conn->binding gate for entering the slowpath is preserved so that non-binding connections keep the fast-path-only behavior, and the session->state check is unchanged.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1e2bec062c5c9ec282636715166056d0998d746dPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1ff46c9915c1cbf454db58a8cb87f7cac818e6a6Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2cc8a4db633b10715450b291c1343859a4b2c509Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/974c1c224e85549dc3459f3bb2255bbbdd2b9372Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b0da97c034b6107d14e537e212d4ce8b22109a58Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e3a93ce6e25757b8f375e38b8f91e1d9da4edc1aPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e74c00c6af428a39e564cdc5bd3a3648c6d8de87Patch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/mgmt/user_session.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "f5a544e3bab78142207e0242d22442db85ba1eff",
              "versionType": "git"
            },
            {
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              "status": "affected",
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              "versionType": "git"
            },
            {
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              "status": "affected",
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              "versionType": "git"
            },
            {
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            },
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              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "f5a544e3bab78142207e0242d22442db85ba1eff",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "f5a544e3bab78142207e0242d22442db85ba1eff",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/mgmt/user_session.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15"
            },
            {
              "lessThan": "5.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.209",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.175",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.141",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.91",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.33",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
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          "negate": false,
          "operator": "OR"
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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: scope conn-\u003ebinding slowpath to bound sessions only\n\nWhen the binding SESSION_SETUP sets conn-\u003ebinding = true, the flag stays\nset after the call so that the global session lookup in\nksmbd_session_lookup_all() can find the session, which was not added to\nconn-\u003esessions. Because the flag is connection-wide, the global lookup\npath will also resolve any other session by id if asked.\n\nTighten the global lookup so that the returned session must have this\nconnection registered in its channel xarray (sess-\u003eksmbd_chann_list).\nThe channel entry is installed by the existing binding_session path in\nntlm_authenticate()/krb5_authenticate() when a SESSION_SETUP completes\nsuccessfully, so this condition is a strict equivalent of \"this\nconnection has been accepted as a channel of this session\". Connections\nthat have not bound to a given session cannot reach it via the global\ntable.\n\nThe existing conn-\u003ebinding gate for entering the slowpath is preserved\nso that non-binding connections keep the fast-path-only behavior, and\nthe session-\u003estate check is unchanged."
    }
  ],
  "id": "CVE-2026-52911",
  "lastModified": "2026-07-08T15:13:12.627",
  "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": "2026-06-21T08:16:23.607",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
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      "url": "https://git.kernel.org/stable/c/1e2bec062c5c9ec282636715166056d0998d746d"
    },
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    },
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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"
    }
  ]
}



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