CVE-2025-53786:

Microsoft Exchange Server vulnerability affecting hybrid deployments, requiring security changes and hotfix installation.

Score
A numerical rating that indicates how dangerous this vulnerability is.

8.0High

Published Date:Aug 6, 2025
CISA KEV Date:*No Data*
Industries Affected:20

Threat Predictions

EPSS Score:0.1
EPSS Percentile:31%

Exploitability

Score:1.3
Attack Vector:NETWORK
Attack Complexity:HIGH
Privileges Required:HIGH
User Interaction:NONE
Scope:CHANGED

Impact

Score:6.0
Confidentiality Impact:HIGH
Integrity Impact:HIGH
Availability Impact:HIGH

Description Preview

Microsoft Exchange Server vulnerability affecting hybrid deployments, requiring security changes and hotfix installation.

Overview

Microsoft announced security changes for Exchange Server hybrid deployments on April 18th, 2025, along with a non-security hotfix. Further investigation revealed specific security implications related to the announced guidance and configuration steps. CVE-2025-53786 documents this vulnerability, which can be addressed by following the steps outlined in the April announcement. The vulnerability affects Exchange Server Subscription editions, as well as Exchange Server 2016 Cumulative Update 23 and Exchange Server 2019 Cumulative Updates 14 and 15. It is associated with CWE-287, suggesting potential issues with improper authentication.

Remediation

To address CVE-2025-53786, Microsoft strongly recommends the following actions:
1. Review the information provided in the April 18th, 2025 announcement.
2. Install the April 2025 (or later) hotfix for affected Exchange Server versions.
3. Implement the recommended changes in your Exchange Server and hybrid environment as outlined in the announcement.
These steps are crucial for improving the security of hybrid Exchange deployments and mitigating the specific vulnerability identified.