Microsoft has released an urgent out-of-band security update to address a critical remote code execution (RCE) vulnerability in Windows Server Update Services (WSUS). The flaw tracked as CVE-2025-59287, poses a direct risk to organizations that utilizes WSUS to manage Windows updates. Severity level: CVSS Score: 9.8 /Critical Description: Windows Server Update Services (WSUS) is a widely used Microsoft tool for managing the distribution of updates in enterprise environments. CVE-2025-59287 is a critical deserialization of untrusted data vulnerability that may allow an unauthorized attacker to execute code on vulnerable machines by sending a specially crafted event to the WSUS server. No user interaction is required to trigger it. Affected Versions: Windows Server 2012 through 2025 with WSUS role enabled. Impact: Successful exploitation allows attackers to execute arbitrary code with System-level privileges. Resolution: Please update to the latest patched versions of Windows Server as provided by Microsoft. If immediate patching is not feasible:
Disable the WSUS role temporarily.
Block inbound traffic to ports 8530 and 8531 to mitigate exposure.
