# KB4021558: June 2017 security update

KB4021558, released June 13, 2017, fixes 6 CVEs across 9 products. None of them is reported as exploited. Patch Radar priority: Urgent. The product is no longer supported.

- Web page: https://patchblox.com/security/fix/microsoft/kb4021558
- Platform: Microsoft
- Released: Jun 13, 2017
- Priority: Urgent (Closes CVE-2016-3326, exploitation more likely)
- CVEs: 6, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://support.microsoft.com/help/4021558

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [Internet Explorer 10 on Windows Server 2012](https://patchblox.com/security/data/product/microsoft/internet-explorer-10-on-windows-server-2012.md) |  |  |
| [Internet Explorer 11 on Windows 7 for 32-bit Systems Service Pack 1](https://patchblox.com/security/data/product/microsoft/internet-explorer-11-on-windows-7-for-32-bit-systems-service-pack-1.md) |  |  |
| [Internet Explorer 11 on Windows 7 for x64-based Systems Service Pack 1](https://patchblox.com/security/data/product/microsoft/internet-explorer-11-on-windows-7-for-x64-based-systems-service-pack-1.md) |  |  |
| [Internet Explorer 11 on Windows 8.1 for 32-bit systems](https://patchblox.com/security/data/product/microsoft/internet-explorer-11-on-windows-8.1-for-32-bit-systems.md) |  |  |
| [Internet Explorer 11 on Windows 8.1 for x64-based systems](https://patchblox.com/security/data/product/microsoft/internet-explorer-11-on-windows-8.1-for-x64-based-systems.md) |  |  |
| [Internet Explorer 11 on Windows Server 2008 R2 for x64-based Systems Service Pack 1](https://patchblox.com/security/data/product/microsoft/internet-explorer-11-on-windows-server-2008-r2-for-x64-based-systems-service-pack-1.md) |  |  |
| [Internet Explorer 11 on Windows Server 2012 R2](https://patchblox.com/security/data/product/microsoft/internet-explorer-11-on-windows-server-2012-r2.md) |  |  |
| [Internet Explorer 9 on Windows Server 2008 for 32-bit Systems Service Pack 2](https://patchblox.com/security/data/product/microsoft/internet-explorer-9-on-windows-server-2008-for-32-bit-systems-service-pack-2.md) |  |  |
| [Internet Explorer 9 on Windows Server 2008 for x64-based Systems Service Pack 2](https://patchblox.com/security/data/product/microsoft/internet-explorer-9-on-windows-server-2008-for-x64-based-systems-service-pack-2.md) |  |  |

## CVEs this fix closes

| CVE | Priority | Component | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2016-3326](https://patchblox.com/security/data/cve/CVE-2016-3326.md) | Urgent | Microsoft Browsers | 2.4 | 0.1585 | More likely |
| [CVE-2017-8524](https://patchblox.com/security/data/cve/CVE-2017-8524.md) | Urgent | Microsoft Scripting Engine | 4.2 | 0.0979 | More likely |
| [CVE-2017-8522](https://patchblox.com/security/data/cve/CVE-2017-8522.md) | Urgent | Microsoft Scripting Engine | 7.5 | 0.0822 | More likely |
| [CVE-2017-8517](https://patchblox.com/security/data/cve/CVE-2017-8517.md) | Urgent | Microsoft Scripting Engine | 6.4 | 0.0822 | More likely |
| [CVE-2017-8519](https://patchblox.com/security/data/cve/CVE-2017-8519.md) | Routine | Internet Explorer | 6.4 | 0.0612 |  |
| [CVE-2017-8547](https://patchblox.com/security/data/cve/CVE-2017-8547.md) | Routine | Internet Explorer | 6.4 | 0.0612 |  |

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Data as of 2026-11-07T06:34:28Z 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