Incorrect Authorization in Microsoft Exchange Online

Publication date: 2026-07-02

Last updated on: 2026-07-02

Assigner: Microsoft Corporation

Description

Incorrect authorization in Microsoft Exchange Online allows an authorized attacker to elevate privileges over a network.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-07-02

Last Modified

2026-07-02

Generated

2026-07-03

AI Q&A

2026-07-03

EPSS Evaluated

N/A

NVD

CVE-2026-54998

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	exchange_online	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-863	The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

Attack-Flow Graph

Executive Summary

This vulnerability is an incorrect authorization issue in Microsoft Exchange Online. It allows an attacker who is already authorized to elevate their privileges over a network, meaning they can gain higher access rights than intended.

Impact Analysis

The vulnerability can have a significant impact as it allows an attacker with some level of authorization to escalate their privileges. This can lead to full compromise of confidentiality, integrity, and availability of the affected system or data.

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