CVE-2025-53782: Microsoft Exchange Server

High severity, CVSS 7.8. EPSS: 0.4% chance of exploitation in the next 30 days.

Incorrect implementation of authentication algorithm in Microsoft Exchange Server allows an unauthorized attacker to elevate privileges locally.

Affected products

• Microsoft Exchange Server: version 2016 only; version 2019 only
• Microsoft Exchange Server Subscription Edition: before 15.02.2562.029 (fixed in 15.02.2562.029)

Published 2025-10-14. Last modified 2026-06-17.