CVE-2026-20856

HIGH
2026-01-13 [email protected]
8.1
CVSS 3.1
Share

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

2
Analysis Generated
Mar 12, 2026 - 21:54 vuln.today
CVE Published
Jan 13, 2026 - 18:16 nvd
HIGH 8.1

Tags

Windows Windows Server 2025 Windows Server 2022 Windows Server 2016 Windows 11 25h2 Windows Server 2012 Windows 10 21h2 Windows 10 22h2 Windows 11 23h2 Windows 10 1607 Windows Server 2022 23h2 Windows 10 1809 Windows 11 24h2 Windows Server 2019 Microsoft

Description

Improper input validation in Windows Server Update Service allows an unauthorized attacker to execute code over a network.

Analysis

Remote code execution in Windows Server Update Service affects Windows 11 25h2, Windows Server 2025, 2022, and 2016 due to inadequate input validation, enabling unauthenticated network-based attackers to execute arbitrary code with high impact. The vulnerability requires specific conditions to exploit (high complexity) but carries significant risk across widely-deployed server infrastructure with no patch currently available.

Sign in for full analysis, threat intelligence, and remediation guidance.

Remediation

Within 7 days: Identify all affected systems and apply vendor patches promptly. Monitor vendor channels for patch availability.

Sign in for detailed remediation steps.

Full analysis requires sign-in

Get intelligence summaries, risk assessment, exploit details, threat intel, and remediation guidance.

Sign in - Free

Priority Score

41
Low Medium High Critical
KEV: 0
EPSS: +0.1
CVSS: +40
POC: 0

Share

CVE-2026-20856 vulnerability details – vuln.today
Back

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy