# CVE-2019-0586: Microsoft Exchange Memory Corruption Vulnerability

CVE-2019-0586 is fixed in 3 products on 1 platform, first by KB4471389, released January 8, 2019. It is not reported as exploited, but the vendor rates exploitation more likely. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/cve/CVE-2019-0586
- Priority: Urgent
- CVSS: n/a (Important)
- EPSS: 0.1540
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation More Likely
- Published: Jan 8, 2019
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2019-0586

## Description

<p>A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the System user. An attacker could then install programs; view, change, or delete data; or create new accounts.</p> <p>Exploitation of the vulnerability requires that a specially crafted email be sent to a vulnerable Exchange server.</p> <p>The security update addresses the vulnerability by correcting how Microsoft Exchange handles objects in memory.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 10 |  | [KB4471389](https://patchblox.com/security/data/fix/microsoft/kb4471389.md) | Jan 8, 2019 |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 11 |  | [KB4471389](https://patchblox.com/security/data/fix/microsoft/kb4471389.md) | Jan 8, 2019 |
| Microsoft | Microsoft Exchange Server 2019 |  | [KB4471389](https://patchblox.com/security/data/fix/microsoft/kb4471389.md) | Jan 8, 2019 |

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Data as of 2026-11-07T18:46:35Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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