CVE-2026-64257

CriticalCVSS 9.1/10Last modified Aug 17, 2026

Description

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.

Metrics

CVSS 3.1 9.1/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Affected software

No affected versions have been published.

Timeline

Published
Jul 25, 2026
Last modified
Aug 17, 2026
NVD status
Analyzed

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CVE-2026-64257: Critical severity, CVSS 9.1 | Vulnix