SB2026011390 - Multiple vulnerabilities in Microsoft Windows SMB Server
Published: January 13, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 6 secuirty vulnerabilities.
1) Race condition (CVE-ID: CVE-2026-20848)
The vulnerability allows a remote attacker to escalate privileges on the system.
The vulnerability exists due to a race condition in Windows SMB Server. A remote user can exploit the race and escalate privileges on the system.
2) Race condition (CVE-ID: CVE-2026-20926)
The vulnerability allows a remote attacker to escalate privileges on the system.
The vulnerability exists due to a race condition in Windows SMB Server. A remote user can exploit the race and escalate privileges on the system.
3) Race condition (CVE-ID: CVE-2026-20919)
The vulnerability allows a remote attacker to escalate privileges on the system.
The vulnerability exists due to a race condition in Windows SMB Server. A remote user can exploit the race and escalate privileges on the system.
4) Race condition (CVE-ID: CVE-2026-20921)
The vulnerability allows a remote attacker to escalate privileges on the system.
The vulnerability exists due to a race condition in Windows SMB Server. A remote user can exploit the race and escalate privileges on the system.
5) Race condition (CVE-ID: CVE-2026-20927)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a race condition in Windows SMB Server. A remote user can exploit the race and cause a denial of service condition on the target system.
6) Race condition (CVE-ID: CVE-2026-20934)
The vulnerability allows a remote attacker to escalate privileges on the system.
The vulnerability exists due to a race condition in Windows SMB Server. A remote user can exploit the race and escalate privileges on the system.
Remediation
Install update from vendor's website.
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20848
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20926
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20919
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20921
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20927
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20934