Vulnerability DatabaseCVE-2025-59249

CVE-2025-59249:
vulnerability analysis and mitigation

Overview

A weak authentication vulnerability (CVE-2025-59249) was discovered in Microsoft Exchange Server, disclosed on October 14, 2025. The vulnerability affects multiple versions of Microsoft Exchange Server including Exchange Server 2016, 2019, and Subscription Edition RTM (NVD, Rapid7).

Technical details

The vulnerability is classified with a CVSS v3.1 base score of 8.8 (HIGH), with the following vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. The attack vector is network-based, requires low attack complexity, needs low privileges, and no user interaction. The vulnerability is categorized under CWE-1390 (Weak Authentication) (NVD).

Impact

If exploited, this vulnerability allows an authorized attacker to elevate privileges over a network, potentially leading to complete system compromise with high impacts on confidentiality, integrity, and availability of the affected system (Rapid7).

Mitigation and workarounds

Microsoft has released security updates to address this vulnerability. Affected users should apply the latest cumulative updates: KB5066369 for Exchange Server 2016 CU23, KB5066368 for Exchange Server 2019 CU14, KB5066367 for Exchange Server 2019 CU15, and updates for Exchange Server Subscription Edition RTM (Microsoft Support).