CVE-2026-21527: Microsoft Exchange Server

Medium severity, CVSS 6.5. EPSS: 8.3% chance of exploitation in the next 30 days.

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

Affected products

• Microsoft Exchange Server: version 2016 only; version 2019 only
• Microsoft Exchange Server Subscription Edition: before 15.02.2562.037 (fixed in 15.02.2562.037)

Published 2026-02-10. Last modified 2026-06-17.