Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

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CVE-2026-64257

Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
25/07/2026
Last modified:
30/07/2026

Description

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> smb: client: reject overlapping data areas in SMB2 responses<br /> <br /> Commit 53b7c271f06b ("smb: client: restrict implied bcc[0] exemption to<br /> responses without data area") restricted the implied bcc[0] length<br /> exception to responses without a data area. However, the overlap<br /> handling in __smb2_calc_size() clears data_length, which can make an<br /> invalid response appear to have no data area and so qualify for the<br /> exception.<br /> <br /> Track data area overlap separately and reject such responses before<br /> applying the length compatibility exceptions.

Impact

Vector 3.x
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 9.10 CRITICAL
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): None
Availability (A): High

Base Score 3.x
9.10
Severity 3.x
CRITICAL

References to Advisories, Solutions, and Tools