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OpenAdvisories
High · 8.0 Exploitation more likely Public exploit CVE-2025-53786 EUVD-2025-23857GHSA-v92c-556h-xm93

Microsoft Exchange Server Hybrid Deployment Elevation of Privilege Vulnerability

Published Aug 6, 2025 · Updated Feb 26, 2026 · Assigned by microsoft

Vendor: Microsoft Product: Microsoft Exchange Server 2016 Cumulative Update 23 Product: Microsoft Exchange Server 2019 Cumulative Update 14 Product: Microsoft Exchange Server 2019 Cumulative Update 15 Product: Microsoft Exchange Server Subscription Edition RTM

Description

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.

Affected products

VendorProductAffectedFixed
Microsoft Microsoft Exchange Server 2016 Cumulative Update 23 15.01.0.0 – < 15.01.2507.055 15.01.2507.055
Microsoft Microsoft Exchange Server 2019 Cumulative Update 14 15.02.0.0 – < 15.02.1544.025 15.02.1544.025
Microsoft Microsoft Exchange Server 2019 Cumulative Update 15 15.02.0.0 – < 15.02.1748.024 15.02.1748.024
Microsoft Microsoft Exchange Server Subscription Edition RTM 15.02.0.0 – < 15.02.2562.017 15.02.2562.017

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 1 repository

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Advisories 5

References