CVE-2026-45501: Microsoft Exchange Server Spoofing Vulnerability

Overview

Severity

Medium (CVSS 6.5)

CVSS Vector

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

Category

Spoofing

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2026-Jun

Released

2026-06-09

Description

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

Affected Products (4)

Server Software

• Microsoft Exchange Server Subscription Edition RTM

ESU

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

Security Updates (1)

• 5094139

Acknowledgments

MARIOS GYFTOS, <a href="https://smlijun.github.io/">DongJun Kim (smlijun)</a> with UIUC, Hwiwon Lee (hwiwonl) with UIUC, Jongseong Kim (nevul37) with UIUC, <a href="https://www.linkedin.com/in/talha--gunay/">TALHA G&#220;NAY</a>, Younggi Park (grill66) with UIUC, <a href="https://www.linkedin.com/in/artemy-tsetsersky/">Artemy Tsetsersky</a> with <a href="https://www.angarasecurity.ru/">Angara Security</a>

Revision History

• 2026-06-09: Information published.