CVE-2026-55006: Microsoft Exchange Server Elevation of Privilege Vulnerability

Overview

Severity

High (CVSS 7.8)

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Category

Elevation of Privilege

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2026-Jul

Released

2026-07-14

Description

Insufficient granularity of access control in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.

Affected Products (4)

ESU

• Microsoft Exchange Server 2019 Cumulative Update 14
• Microsoft Exchange Server 2019 Cumulative Update 15
• Microsoft Exchange Server 2016 Cumulative Update 23

Server Software

• Microsoft Exchange Server Subscription Edition RTM

Security Updates (1)

• 5103212

Acknowledgments

MARIOS GYFTOS

Revision History

• 2026-07-14: Information published.