CVE-2026-42897: Microsoft Exchange Server Cross-Site Scripting Vulnerability

Medium severity, CVSS 6.1. Actively exploited: in CISA KEV since 2026-05-15. EPSS: 0.5% chance of exploitation in the next 30 days.

Improper neutralization of input during web page generation ('cross-site scripting') 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 15.02.2562.043 (fixed in 15.02.2562.043)

Published 2026-05-14. Last modified 2026-06-17.