SB20260812406 - Improper access control in Linux kernel smb server



SB20260812406 - Improper access control in Linux kernel smb server

Published: August 12, 2026

Security Bulletin ID SB20260812406
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Improper access control (CVE-ID: CVE-2026-68130)

CWE-ID: CWE-284 - Improper Access Control

CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote user to cause a denial of service.

The vulnerability exists due to improper access control in ntlm_authenticate() when processing an NTLM authentication request containing a crafted username field and PreviousSessionId. A remote user can supply a username matching a victim account and a victim session identifier to cause a denial of service.

The issue can destroy another user's SMB session before the NTLMv2 response is validated.


Remediation

Install update from vendor's website.