GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

FKIE_CVE-2026-68130

Vulnerability from fkie_nvd - Published: 2026-08-10 13:19 - Updated: 2026-08-23 13:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: defer destroy_previous_session() until after NTLM authentication In ntlm_authenticate(), destroy_previous_session() is called using a user pointer resolved from the client-supplied NTLM blob username field before the NTLMv2 response is validated. An authenticated attacker can set the NTLM blob username to match a victim account and set PreviousSessionId to the victim's session ID; destroy_previous_session() destroys the victim's session while ksmbd_decode_ntlmssp_auth_blob() subsequently rejects the request with -EPERM. Move destroy_previous_session() and the prev_id assignment to after ksmbd_decode_ntlmssp_auth_blob() returns success and use sess->user rather than the pre-authentication lookup result. This matches the ordering already used by krb5_authenticate(), where destroy_previous_session() is called only after ksmbd_krb5_authenticate() returns success.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0ff12308c8a6c16ab68f0a487ffa93d69001dc18
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/18705cace0619fd2123737dcd028147774f38181
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/243f1614ef2aca2d62a744575f1c24b07cd42757
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/370b0ec8822b69c9073265e16b7daaa8201c9a4f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5c833074b549e5db125436a6f681af682261f785
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ab0230257ebdf48b07eaa679a8c92bc842fe3498
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c74801ee524f477c174a1899782b6c3b6918d407
Impacted products
Vendor Product Version
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": "ab0230257ebdf48b07eaa679a8c92bc842fe3498",
              "status": "affected",
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "versionType": "git"
            },
            {
              "lessThan": "370b0ec8822b69c9073265e16b7daaa8201c9a4f",
              "status": "affected",
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "versionType": "git"
            },
            {
              "lessThan": "5c833074b549e5db125436a6f681af682261f785",
              "status": "affected",
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "versionType": "git"
            },
            {
              "lessThan": "243f1614ef2aca2d62a744575f1c24b07cd42757",
              "status": "affected",
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "versionType": "git"
            },
            {
              "lessThan": "18705cace0619fd2123737dcd028147774f38181",
              "status": "affected",
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "versionType": "git"
            },
            {
              "lessThan": "0ff12308c8a6c16ab68f0a487ffa93d69001dc18",
              "status": "affected",
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "versionType": "git"
            },
            {
              "lessThan": "c74801ee524f477c174a1899782b6c3b6918d407",
              "status": "affected",
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/smb2pdu.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": "5.15.217",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: defer destroy_previous_session() until after NTLM authentication\n\nIn ntlm_authenticate(), destroy_previous_session() is called using a\nuser pointer resolved from the client-supplied NTLM blob username field\nbefore the NTLMv2 response is validated. An authenticated attacker can\nset the NTLM blob username to match a victim account and set\nPreviousSessionId to the victim\u0027s session ID; destroy_previous_session()\ndestroys the victim\u0027s session while ksmbd_decode_ntlmssp_auth_blob()\nsubsequently rejects the request with -EPERM.\n\nMove destroy_previous_session() and the prev_id assignment to after\nksmbd_decode_ntlmssp_auth_blob() returns success and use sess-\u003euser\nrather than the pre-authentication lookup result. This matches the\nordering already used by krb5_authenticate(), where\ndestroy_previous_session() is called only after\nksmbd_krb5_authenticate() returns success."
    }
  ],
  "id": "CVE-2026-68130",
  "lastModified": "2026-08-23T13:16:33.353",
  "metrics": {},
  "published": "2026-08-10T13:19:58.337",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0ff12308c8a6c16ab68f0a487ffa93d69001dc18"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/18705cace0619fd2123737dcd028147774f38181"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/243f1614ef2aca2d62a744575f1c24b07cd42757"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/370b0ec8822b69c9073265e16b7daaa8201c9a4f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5c833074b549e5db125436a6f681af682261f785"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ab0230257ebdf48b07eaa679a8c92bc842fe3498"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c74801ee524f477c174a1899782b6c3b6918d407"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.


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.