SB2026051304 - Privilege escalation in Microsoft Windows SMB Client



SB2026051304 - Privilege escalation in Microsoft Windows SMB Client

Published: May 13, 2026

Security Bulletin ID SB2026051304
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Code execution

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Use-after-free (CVE-ID: CVE-2026-40410)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a local user to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in Windows SMB Client. A local user can win a race condition and gain elevated privileges on the system.


Remediation

Install update from vendor's website.