CVE-2026-62915: Microsoft Exchange Server Security Feature Bypass Vulnerability

Overview

Severity

Medium (CVSS 6.5)

CVSS Vector

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

Category

Security Feature Bypass

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2026-Aug

Released

2026-08-11

Description

Missing authorization in Microsoft Exchange Server allows an authorized attacker to bypass a security feature over a network.

FAQ

What kind of security feature could be bypassed by successfully exploiting this vulnerability? An authenticated attacker who successfully exploited this vulnerability could bypass a role-based restriction that is intended to control which users are allowed to install mail add-ins. By bypassing this control, a user could install an add-in that requests elevated mailbox permissions that an administrator's policy was meant to prevent.

Affected Products (4)

ESU

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

Server Software

• Microsoft Exchange Server Subscription Edition RTM

Security Updates (1)

• 5121573

Acknowledgments

<a href="https://www.linkedin.com/in/navaponpremkasem/">71C4</a>

Revision History

• 2026-08-11: Information published.