SB2026011499 - Multiple vulnerabilities in Microsoft Windows Kernel

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Information Exposure Through an Error Message (CVE-ID: CVE-2026-20838)

The vulnerability allows a local user to gain access to potentially sensitive information.

The vulnerability exists due to generation of error message containing sensitive information in Windows Kernel. A local user can gain unauthorized access to sensitive information on the system.

2) Time-of-check Time-of-use (TOCTOU) Race Condition (CVE-ID: CVE-2026-20809)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a time-of-check, time-of-use (TOCTOU) race condition in Windows Kernel. A local user can gain elevated privileges on the target system.

3) Inclusion of Sensitive Information in Log Files (CVE-ID: CVE-2026-20818)

The vulnerability allows a local attacker to gain access to sensitive information.

The vulnerability exists due to software stores sensitive information into log files in Windows Kernel. A local attacker can read the log files and gain access to sensitive data.

Remediation

Install update from vendor's website.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20838
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20809
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20818