What’s Vulnerable › Vulnerabilities
CVE-2025-53786: Microsoft Exchange Server Hybrid Deployment Elevation of Privilege Vulnerability
- Severity: high (CVSS 8.0 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 7.7% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2025-08-06 · updated 2026-06-17
- Weakness: CWE-287
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
- Microsoft Exchange Server: 2016-cumulative_update_23, 2019-cumulative_update_14, 2019-cumulative_update_15
- Microsoft Exchange Server Subscription Edition: before 15.02.2562.017 — fixed in 15.02.2562.017
- Microsoft Exchange Server 2016 Cumulative Update 23: from 15.01.0.0 before 15.01.2507.055 — fixed in 15.01.2507.055
- Microsoft Exchange Server 2019 Cumulative Update 14: from 15.02.0.0 before 15.02.1544.025 — fixed in 15.02.1544.025
- Microsoft Exchange Server 2019 Cumulative Update 15: from 15.02.0.0 before 15.02.1748.024 — fixed in 15.02.1748.024
- Microsoft Exchange Server Subscription Edition RTM: from 15.02.0.0 before 15.02.2562.017 — fixed in 15.02.2562.017
How to fix
Upgrade to a fixed version: Microsoft Exchange Server Subscription Edition 15.02.2562.017; Microsoft Exchange Server 2016 Cumulative Update 23 15.01.2507.055; Microsoft Exchange Server 2019 Cumulative Update 14 15.02.1544.025; Microsoft Exchange Server 2019 Cumulative Update 15 15.02.1748.024; Microsoft Exchange Server Subscription Edition RTM 15.02.2562.017. Check the vendor advisory for mitigations.
References
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