cve 2025 64666

CVE-2025-64666 is a high-severity elevation of privilege vulnerability in Microsoft Exchange Server, caused by improper input validation. With a CVSS v3.1 base score of approximately 7.5, this issue requires immediate attention from administrators managing on-premises or hybrid Exchange infrastructure. The public record indicates that Microsoft has cataloged this vulnerability, and vendors list it as an Exchange Server elevation of privilege flaw. Administrators should verify whether their Exchange builds are affected and apply the appropriate security update or cumulative package from Microsoft to mitigate the risk. This tag covers discussions and guidance related to CVE-2025-64666, including patch management and remediation steps for Exchange Server environments.