CVE-2026-45503

Analyzed Analyzed - Analysis Complete

Improper Authorization in Microsoft Exchange Server

Publication date: 2026-06-09

Last updated on: 2026-06-15

Assigner: Microsoft Corporation

Description

Server-side request forgery (ssrf) in Microsoft Exchange Server allows an authorized attacker to disclose information over a network.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-06-09

Last Modified

2026-06-15

Generated

2026-06-30

AI Q&A

2026-06-09

EPSS Evaluated

2026-06-28

NVD

CVE-2026-45503

EUVD

EUVD-2026-35679

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	exchange_server	2016
microsoft	exchange_server	2019
microsoft	exchange_server	2019
microsoft	exchange_server_subscription_edition	to 15.02.2562.043 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-285	The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.
CWE-918	The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

Attack-Flow Graph

Compliance Impact

This vulnerability in Microsoft Exchange Server allows an authorized attacker to disclose information over a network due to improper authorization.

Such information disclosure could potentially impact compliance with data protection standards and regulations like GDPR and HIPAA, which require safeguarding sensitive information against unauthorized access and disclosure.

However, the provided information does not specify exact compliance implications or affected data types relevant to these regulations.

Executive Summary

CVE-2026-45503 is a server-side request forgery (SSRF) vulnerability in Microsoft Exchange Server. It allows an authorized attacker to make the server send unauthorized requests, which can lead to the disclosure of sensitive information over a network.

Impact Analysis

This vulnerability can lead to significant information disclosure, allowing an attacker with some level of authorization to access sensitive data over the network. The impact is rated as important with a CVSS base score of 8.1, indicating high confidentiality and integrity risks.

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