CVE-2026-64257 (GCVE-0-2026-64257)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:49 – Updated: 2026-07-27 04:59
VLAI
Title
smb: client: reject overlapping data areas in SMB2 responses
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.
Severity
9.1 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 31c6312608c60b72a1feb99a5afb680645a3e8a3 , < 445ece263131780dee273d727a4d6f11934feec7 (git)
Affected: 573e502d14714d2947e22e7eff40ec20a6a44a42 , < 36bfa52459e45c0d5b668de2f1c91f6dc5c67775 (git)
Affected: 419ec1b604d7fb60c10aec2dc062371f9fcd4940 , < 4a9d2657d3e05f6ed09c148cb127b4e58702275f (git)
Affected: ceb875a375dedbf51c9425c1d13a2d7a8435c08c , < fdafa1e68dc75045b7b617e6e7d2854950804d83 (git)
Affected: 6e9d10f62773b99bd927940fd9cbdfe7207e23ff , < 57cba95f0e97c6f6e45e6731da30aff091bd7460 (git)
Affected: 53b7c271f06be4dd5cfc8c6ef552a8355c891a7f , < 8986c932905ea508d66da421eb2eb6e676ace1fe (git)
Affected: 8d0bbc78046d264bbf6a574ea6f9072258a43e35 (git)
Affected: b6a381c01e2ac98a48e32ac0f2a45bbadd9e26b0 (git)
Affected: 5.10.261 , < 5.11 (semver)
Affected: 5.15.212 , < 5.16 (semver)
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Linux Linux Affected: 7.2-rc3
Unaffected: 0 , < 7.2-rc3 (semver)
Unaffected: 7.2-rc4 , ≤ * (original_commit_for_fix)
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{
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    "dateReserved": "2026-07-19T15:36:31.773Z",
    "dateUpdated": "2026-07-27T04:59:11.315Z",
    "state": "PUBLISHED"
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    "suse_vex": {
      "aggregate_severity": "not set",
      "current_release_date": "2026-07-25T16:47:10Z",
      "cve": "CVE-2026-64257",
      "id": "CVE-2026-64257",
      "initial_release_date": "2026-07-25T16:47:10Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-64257",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64257.json",
      "version": "2"
    }
  }
}



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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.