CVE-2026-55007: Microsoft Exchange Server

High severity, CVSS 8.1. EPSS: 0.7% chance of exploitation in the next 30 days.

Double free in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.

Affected products

• Microsoft Exchange Server: 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 2026-10-05.