CVE-2026-69378: Microsoft Exchange Server

High severity, CVSS 7.5. EPSS: 1.2% chance of exploitation in the next 30 days.

Uncontrolled recursion in Microsoft Exchange Server allows an unauthorized attacker to deny service over a network.

Affected products

• Microsoft Exchange Server: version 2016 only; version 2019 only
• Microsoft Exchange Server Subscription Edition: before 15.02.2562.049 (fixed in 15.02.2562.049)

Published 2026-09-08. Last modified 2026-09-29.