Linux Kernel ksmbd smb_inherit_dacl Out-Of-Bounds Read Information Disclosure Vulnerability

November 13th, 2026
ZDI-26-1003 ZDI-CAN-30364

CVE ID

CVE-2026-64138

CVSS Score

7.1 AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:L

Affected Vendors

Linux

Affected Products

Kernel

Vulnerability Details

This vulnerability allows remote attackers to disclose sensitive information on affected installations of Linux Kernel. Authentication is required to exploit this vulnerability. However, only systems with ksmbd enabled are vulnerable.

The specific flaw exists within the handling of inherited security descriptors. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated buffer. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of the kernel.

Additional Details

Linux has issued an update to correct this vulnerability. More details can be found at:
https://github.com/torvalds/linux/commit/69f030cf95488ae1186c72ac8c66fd279664ea7f

Disclosure Timeline

  • 2026-04-08 - Vulnerability reported to vendor
  • 2026-11-13 - Coordinated public release of advisory
  • 2026-11-13 - Advisory Updated

Credit

Nicholas Zubrisky (@NZubrisky) of TrendAI Research

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