SB2026080617 - Out-of-bounds read in Linux kernel smb server

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Main Vulnerability Database SB2026080617

SB2026080617 - Out-of-bounds read in Linux kernel smb server

Published: August 6, 2026

Security Bulletin ID SB2026080617
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Information disclosure

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Out-of-bounds read (CVE-ID: CVE-2026-64578)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to an out-of-bounds read in ksmbd_smb2_check_message() when processing a crafted compound SMB2 request. A remote attacker can send a specially crafted compound request with a trailing element that is too small to hold StructureSize2 to disclose sensitive information.

The issue occurs when the last compound element contains only a 64-byte SMB2 header, causing a 2-byte read at offset 64 to extend past the receive buffer.


Remediation

Install update from vendor's website.

References