SB2026031060 - Multiple vulnerabilities in Microsoft Windows SMB Server

Description

This security bulletin contains information about 2 vulnerabilities.

1) Improper Authentication (CVE-ID: CVE-2026-26128)

CWE-ID: CWE-287 - Improper Authentication

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

The vulnerability allows a local user to bypass authentication process.

The vulnerability exists due to an error when processing authentication requests in Windows SMB Server. A local user can bypass authentication process and gain unauthorized access to the application.

2) Improper Authentication (CVE-ID: CVE-2026-24294)

CWE-ID: CWE-287 - Improper Authentication

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/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 bypass authentication process.

The vulnerability exists due to an error when processing authentication requests in Windows SMB Server. A local user can bypass authentication process and gain unauthorized access to the application.

Remediation

Install update from vendor's website.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26128
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-24294