Winsage
October 24, 2025
Microsoft released an emergency patch on October 23, 2025, to address a critical remote code execution vulnerability (CVE-2025-59287) in Windows Server Update Services (WSUS). The vulnerability, rated critical with a CVSS score of 9.8, allows unauthorized attackers to execute arbitrary code over the network through unsafe deserialization of untrusted data. Although WSUS is not enabled by default, organizations using it are at risk if unpatched. The CVE's temporal score was updated to 8.8 after proof-of-concept exploit code was confirmed. The patch is available through various Microsoft update channels but requires a server reboot. Temporary workarounds include disabling the WSUS server role or blocking specific inbound traffic. Affected versions include Windows Server 2012, 2012 R2, 2016, 2019, 2022, 2022 (23H2 Edition), and 2025, each with corresponding patch KB numbers.
