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

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.

Published: 2025-08-06 Last update: 2026-02-27 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2025-53786 is rated Moderate Risk (56.1/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.54%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-53786

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-02 0.26% 0.54% +0.28%
2 2026-05-02 0.22% 0.26% +0.04%
3 2026-04-22 0.22%

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-53786

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.0 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.3 6.0 [email protected]

Weakness enumeration for CVE-2025-53786

Affected software / configurations for CVE-2025-53786

Vendor Product Version Raw CPE
microsoft exchange_server cpe:2.3:a:microsoft:exchange_server:-:*:*:*:subscription:*:*:*
microsoft exchange_server 2016 cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_23:*:*:*:*:*:*
microsoft exchange_server 2019 cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_14:*:*:*:*:*:*
microsoft exchange_server 2019 cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_15:*:*:*:*:*:*

References for CVE-2025-53786

cvelogic Threat Intelligence