Linux Kernel ksmbd Share Configuration Race Condition Remote Code Execution Vulnerability

September 14th, 2026
ZDI-26-693 ZDI-CAN-29790

CVE ID

CVSS Score

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

Affected Vendors

Linux

Affected Products

Kernel

Vulnerability Details

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Linux Kernel. Authentication is required to exploit this vulnerability. Furthermore, only systems with ksmbd enabled are vulnerable.

The specific flaw exists within the handling of share_conf objects. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to execute 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/5258572aa5fd5a7ed01b123b28241e0281b6fb9b

Disclosure Timeline

  • 2026-03-30 - Vulnerability reported to vendor
  • 2026-09-14 - Coordinated public release of advisory
  • 2026-09-14 - Advisory Updated

Credit

DongHyeon Hwang (kind_killerwhale)

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