# CVE-2025-59249: Microsoft Exchange Server Elevation of Privilege Vulnerability

CVE-2025-59249 is fixed in 4 products on 1 platform, first by KB5066369, released October 14, 2025. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2025-59249
- Priority: High
- CVSS: 8.8 (Important)
- EPSS: 0.0085
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation Unlikely
- Published: Oct 14, 2025
- Weakness: Weak Authentication
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-59249

## Description

<p>Weak authentication in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 23 |  | [KB5066369](https://patchblox.com/security/data/fix/microsoft/kb5066369.md) | Oct 14, 2025 |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 14 |  | [KB5066368](https://patchblox.com/security/data/fix/microsoft/kb5066368.md) | Oct 14, 2025 |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 15 |  | [KB5066367](https://patchblox.com/security/data/fix/microsoft/kb5066367.md) | Oct 14, 2025 |
| Microsoft | Microsoft Exchange Server Subscription Edition RTM |  | [KB5066366](https://patchblox.com/security/data/fix/microsoft/kb5066366.md) | Oct 14, 2025 |

---

Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.