Linux Kernel KSMBD Response Header Out-Of-Bounds Read Information Disclosure Vulnerability

August 13th, 2026
ZDI-26-573 ZDI-CAN-31063

CVE ID

CVSS Score

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

Affected Vendors

Linux

Affected Products

Kernel KSMBD

Vulnerability Details

This vulnerability allows remote attackers to disclose sensitive information on affected installations of Linux Kernel KSMBD. Authentication is not required to exploit this vulnerability. However, only systems with ksmbd enabled are vulnerable.

The specific flaw exists within the init_smb2_rsp_hdr functions. 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/cfc0b8e5080aec87700774e8568765eaa4b7b92b

Disclosure Timeline

  • 2026-07-03 - Vulnerability reported to vendor
  • 2026-08-13 - Coordinated public release of advisory
  • 2026-08-13 - Advisory Updated

Credit

p2gone

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