# CVE-2018-8265: Microsoft Exchange Remote Code Execution Vulnerability

CVE-2018-8265 is fixed in 2 products on 1 platform, first by KB4459266, released October 9, 2018. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2018-8265
- Priority: High
- CVSS: n/a (Important)
- EPSS: 0.1927
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation Less Likely
- Published: Oct 9, 2018
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2018-8265

## Description

<p>A remote code execution vulnerability exists in the way Microsoft Exchange software parses specially crafted email messages.  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, add, or delete data.</p> <p>To exploit this vulnerability, an attacker would need to send a specially crafted email to an affected Exchange server, and then convince the recipient to perform multiple actions while replying to the message.</p> <p>The security update addresses the vulnerability by correcting how Microsoft Exchange parses specially crafted email messages.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Microsoft Exchange Server 2013 Cumulative Update 21 |  | [KB4459266](https://patchblox.com/security/data/fix/microsoft/kb4459266.md) | Oct 9, 2018 |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 10 |  | [KB4459266](https://patchblox.com/security/data/fix/microsoft/kb4459266.md) | Oct 9, 2018 |

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Data as of 2026-11-07T12:40:37Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo