# CVE-2026-44817: Microsoft Excel Remote Code Execution Vulnerability

CVE-2026-44817 is fixed in 3 products on 1 platform, first by KB5002877, released June 9, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-44817
- Priority: High
- CVSS: 7.8 (Important)
- EPSS: 0.0037
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation Unlikely
- Published: Jun 9, 2026
- Weakness: Access of Resource Using Incompatible Type ('Type Confusion')
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-44817

## Description

<p>Access of resource using incompatible type ('type confusion') in Microsoft Office Excel allows an unauthorized attacker to execute code locally.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Microsoft Excel 2016 (32-bit edition) |  | [KB5002877](https://patchblox.com/security/data/fix/microsoft/kb5002877.md) | Jun 9, 2026 |
| Microsoft | Microsoft Excel 2016 (64-bit edition) |  | [KB5002877](https://patchblox.com/security/data/fix/microsoft/kb5002877.md) | Jun 9, 2026 |
| Microsoft | Office Online Server |  | [KB5002875](https://patchblox.com/security/data/fix/microsoft/kb5002875.md) | Jun 9, 2026 |

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Data as of 2026-11-08T13:06:02Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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