FKIE_CVE-2026-64257

Vulnerability from fkie_nvd - Published: 2026-07-25 10:17 - Updated: 2026-07-27 05:16
Severity
9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: smb: client: reject overlapping data areas in SMB2 responses Commit 53b7c271f06b ("smb: client: restrict implied bcc[0] exemption to responses without data area") restricted the implied bcc[0] length exception to responses without a data area. However, the overlap handling in __smb2_calc_size() clears data_length, which can make an invalid response appear to have no data area and so qualify for the exception. Track data area overlap separately and reject such responses before applying the length compatibility exceptions.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/36bfa52459e45c0d5b668de2f1c91f6dc5c67775
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/445ece263131780dee273d727a4d6f11934feec7
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4a9d2657d3e05f6ed09c148cb127b4e58702275f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/57cba95f0e97c6f6e45e6731da30aff091bd7460
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/8986c932905ea508d66da421eb2eb6e676ace1fe
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fdafa1e68dc75045b7b617e6e7d2854950804d83
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/client/smb2misc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "445ece263131780dee273d727a4d6f11934feec7",
              "status": "affected",
              "version": "31c6312608c60b72a1feb99a5afb680645a3e8a3",
              "versionType": "git"
            },
            {
              "lessThan": "36bfa52459e45c0d5b668de2f1c91f6dc5c67775",
              "status": "affected",
              "version": "573e502d14714d2947e22e7eff40ec20a6a44a42",
              "versionType": "git"
            },
            {
              "lessThan": "4a9d2657d3e05f6ed09c148cb127b4e58702275f",
              "status": "affected",
              "version": "419ec1b604d7fb60c10aec2dc062371f9fcd4940",
              "versionType": "git"
            },
            {
              "lessThan": "fdafa1e68dc75045b7b617e6e7d2854950804d83",
              "status": "affected",
              "version": "ceb875a375dedbf51c9425c1d13a2d7a8435c08c",
              "versionType": "git"
            },
            {
              "lessThan": "57cba95f0e97c6f6e45e6731da30aff091bd7460",
              "status": "affected",
              "version": "6e9d10f62773b99bd927940fd9cbdfe7207e23ff",
              "versionType": "git"
            },
            {
              "lessThan": "8986c932905ea508d66da421eb2eb6e676ace1fe",
              "status": "affected",
              "version": "53b7c271f06be4dd5cfc8c6ef552a8355c891a7f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8d0bbc78046d264bbf6a574ea6f9072258a43e35",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "b6a381c01e2ac98a48e32ac0f2a45bbadd9e26b0",
              "versionType": "git"
            },
            {
              "lessThan": "5.11",
              "status": "affected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThan": "5.16",
              "status": "affected",
              "version": "5.15.212",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/client/smb2misc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.2-rc3"
            },
            {
              "lessThan": "7.2-rc3",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc4",
              "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\nsmb: client: reject overlapping data areas in SMB2 responses\n\nCommit 53b7c271f06b (\"smb: client: restrict implied bcc[0] exemption to\nresponses without data area\") restricted the implied bcc[0] length\nexception to responses without a data area. However, the overlap\nhandling in __smb2_calc_size() clears data_length, which can make an\ninvalid response appear to have no data area and so qualify for the\nexception.\n\nTrack data area overlap separately and reject such responses before\napplying the length compatibility exceptions."
    }
  ],
  "id": "CVE-2026-64257",
  "lastModified": "2026-07-27T05:16:37.930",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-25T10:17:05.817",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/36bfa52459e45c0d5b668de2f1c91f6dc5c67775"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/445ece263131780dee273d727a4d6f11934feec7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4a9d2657d3e05f6ed09c148cb127b4e58702275f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/57cba95f0e97c6f6e45e6731da30aff091bd7460"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8986c932905ea508d66da421eb2eb6e676ace1fe"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fdafa1e68dc75045b7b617e6e7d2854950804d83"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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