Windows Server 2019 - RCE (CVE-2025-59287)

CVE-2025-59287 is a critical vulnerability in Windows Server Update Service across multiple Windows Server versions, where deserialization of untrusted data allows unauthorized attackers to execute arbitrary code remotely. This flaw could be exploited over a network, potentially leading to full system compromise, data theft, or disruption of services without requiring user interaction.

CrowdSec has been tracking this vulnerability and its exploits since 17th of December 2025.

According to CrowdSec data, while opportunistic exploitation dominates, a portion of threat actors trying to exploit CVE-2025-59287 apply basic targeting methods such as port or service detection. This indicates emerging patterns of selective targeting. CrowdSec data also reveals a clear uptick in attacks involving CVE-2025-59287 over the past week. Activity is above the usual baseline, suggesting growing attention from attackers. This may reflect rising awareness, recent exploit releases, or expanded targeting efforts.

Attackers exploit this vulnerability by sending crafted SOAP/XML requests to WSUS endpoints such as /ReportingWebService/ReportingWebService.asmx, /SimpleAuthWebService/SimpleAuth.asmx, and /ClientWebService/Client.asmx, leveraging insecure deserialization to achieve remote code execution. These exploitation attempts typically involve chained requests to these SOAP services, targeting the deserialization logic in the Windows Server Update Service.