CVE-2025-53786 HIGH

CVE-2025-53786: Microsoft Exchange Server Hybrid Deployment Elevation of Privilege Vulnerability

Vendor Microsoft
Product Microsoft Exchange Server 2016 Cumulative Update 23
Weakness CWE-287 · Improper authentication
Published August 6, 2025
Last update February 26, 2026

CVSS base score

8.0/10
Attack vector Network
Attack complexity High
Privileges required High
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C

What the vulnerability does

01Description

On April 18th 2025, Microsoft announced Exchange Server Security Changes for Hybrid Deployments and accompanying non-security Hot Fix. Microsoft made these changes in the general interest of improving the security of hybrid Exchange deployments. Following further investigation, Microsoft identified specific security implications tied to the guidance and configuration steps outlined in the April announcement. Microsoft is issuing CVE-2025-53786 to document a vulnerability that is addressed by taking the steps documented with the April 18th announcement. Microsoft strongly recommends reading the information, installing the April 2025 (or later) Hot Fix and implementing the changes in your Exchange Server and hybrid environment.

Key dates

02Disclosure timeline

August 6, 2025 CVE published
February 26, 2026 Record updated