CVE-2025-53786

Exchange Server vulnerability

CVSS

8.0

EPSS

7.4%

EPSS pct

94th

Exploited

No known

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 vendor

Microsoft

Affected product

Exchange Server

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H

Weakness type (CWE)

CWE-287 — Improper Authentication

Published

2025-08-06

Risk analysis

Based on its CVSS vector, this vulnerability is exploitable over the network, high attack complexity, requiring high privileges, no user interaction. Successful exploitation leads to high impact to confidentiality, high impact to integrity, high impact to availability.

Its EPSS score of 7.4% reflects a lower probability of exploitation activity in the wild over the next 30 days, placing it above 94% of all scored CVEs.

Check your external exposure to CVE-2025-53786

Confirm whether Microsoft Exchange Server is running on any internet-facing host or subdomain.
Match discovered service fingerprints against the version affected by CVE-2025-53786.
Prioritise remediation if the asset is public, business-critical, or near authentication/payment flows.

How ThreatPort helps with CVE-2025-53786

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