{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "31c6312608c60b72a1feb99a5afb680645a3e8a3"
            },
            {
              "fixed": "445ece263131780dee273d727a4d6f11934feec7"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "573e502d14714d2947e22e7eff40ec20a6a44a42"
            },
            {
              "fixed": "36bfa52459e45c0d5b668de2f1c91f6dc5c67775"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "419ec1b604d7fb60c10aec2dc062371f9fcd4940"
            },
            {
              "fixed": "4a9d2657d3e05f6ed09c148cb127b4e58702275f"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "ceb875a375dedbf51c9425c1d13a2d7a8435c08c"
            },
            {
              "fixed": "fdafa1e68dc75045b7b617e6e7d2854950804d83"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "6e9d10f62773b99bd927940fd9cbdfe7207e23ff"
            },
            {
              "fixed": "57cba95f0e97c6f6e45e6731da30aff091bd7460"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "53b7c271f06be4dd5cfc8c6ef552a8355c891a7f"
            },
            {
              "fixed": "8986c932905ea508d66da421eb2eb6e676ace1fe"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "8d0bbc78046d264bbf6a574ea6f9072258a43e35"
            },
            {
              "last_affected": "b6a381c01e2ac98a48e32ac0f2a45bbadd9e26b0"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "5.10.261"
            },
            {
              "fixed": "5.11"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "5.15.212"
            },
            {
              "fixed": "5.16"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64257.json"
  },
  "details": "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",
  "modified": "2026-08-18T03:31:15.826065650Z",
  "published": "2026-07-25T08:49:09.345Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/36bfa52459e45c0d5b668de2f1c91f6dc5c67775"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/445ece263131780dee273d727a4d6f11934feec7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4a9d2657d3e05f6ed09c148cb127b4e58702275f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/57cba95f0e97c6f6e45e6731da30aff091bd7460"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8986c932905ea508d66da421eb2eb6e676ace1fe"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fdafa1e68dc75045b7b617e6e7d2854950804d83"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64257.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64257"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "smb: client: reject overlapping data areas in SMB2 responses"
}