CVE-2025-53786
Microsoft Exchange Server Hybrid Deployment Authentication Bypass Vulnerability
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.
INFO
Published Date :
Aug. 6, 2025, 4:15 p.m.
Last Modified :
Aug. 6, 2025, 8:23 p.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
6.0
Exploitability Score :
1.3
Affected Products
The following products are affected by CVE-2025-53786
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-53786.
| URL | Resource |
|---|---|
| https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53786 |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-53786 vulnerability anywhere in the article.
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Help Net Security
Microsoft urges admins to plug severe Exchange security hole (CVE-2025-53786)
“In an Exchange hybrid deployment, an attacker who first gains administrative access to an on-premises Exchange server could potentially escalate privileges within the organization’s connected cloud e ... Read more
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The Hacker News
Microsoft Discloses Exchange Server Flaw Enabling Silent Cloud Access in Hybrid Setups
Aug 07, 2025Ravie LakshmananVulnerability / Threat Detection Microsoft has released an advisory for a high-severity security flaw affecting on-premise versions of Exchange Server that could allow an ... Read more
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BleepingComputer
Microsoft warns of high-severity flaw in hybrid Exchange deployments
Microsoft has warned customers to mitigate a high-severity vulnerability in Exchange Server hybrid deployments that could allow attackers to escalate privileges in Exchange Online cloud environments u ... Read more
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The Cyber Express
Microsoft to Pull Plug on Shared EWS Access in Hybrid Exchange by October
Organizations using Exchange hybrid deployments should prepare for new changes taking effect over the next few months. Microsoft has announced that beginning in August 2025, it will temporarily block ... Read more
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security.nl
Microsoft komt met noodpatch voor beveiligingslek in Exchange Server
Microsoft heeft buiten de vaste maandelijkse patchcyclus om noodpatches voor een kwetsbaarheid in Exchange Server uitgebracht en verwacht dat aanvallers misbruik van het beveiligingslek zullen gaan ma ... Read more
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CybersecurityNews
New Microsoft Exchange Server Vulnerability Enables Attackers to Gain Admin Privileges
A critical security vulnerability in Microsoft Exchange Server hybrid deployments has been disclosed, allowing attackers with on-premises administrative access to escalate privileges to cloud environm ... Read more
The following table lists the changes that have been made to the
CVE-2025-53786 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Aug. 06, 2025
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H Added CWE CWE-287 Added Reference https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53786
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-53786 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-53786
weaknesses.