CVE-2026-20856 Windows Server Update Service (WSUS) Remote Code Execution Vulnerability

Api.Msrc.Microsoft • January 13, 2026

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

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CVE-2026-20856: WSUS Remote Code Execution Vulnerability Identified A remote code execution vulnerability, identified as CVE-2026-20856, has been found in Windows Server Update Service (WSUS). This flaw arises from improper input validation, allowing unauthorized attackers to execute code over a network. Affected systems include those running WSUS, which is critical for managing updates in Windows environments. 1 sources 64

Extracted Entities

Attack Types (1)

Remote Code Execution

CVEs (1)