CVE-2026-21527 MEDIUM

CVE-2026-21527: Microsoft Exchange Server Spoofing Vulnerability

Vendor Microsoft
Product Microsoft Exchange Server 2016 Cumulative Update 23
Weakness CWE-451
Published February 10, 2026
Last update May 11, 2026
View on NVD All CVEs

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality Low
Integrity Low

CVSS vector

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

What the vulnerability does

01Description

User interface (ui) misrepresentation of critical information in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.

Key dates

02Disclosure timeline

February 10, 2026 CVE published
May 11, 2026 Record updated