# KB3158991: May 2016 security update

KB3158991, released May 10, 2016, fixes 1 CVE across 7 products. One of them is being exploited (CVE-2016-0189); 1 on CISA KEV. Patch Radar priority: Patch now. The product is no longer supported.

- Web page: https://patchblox.com/security/fix/microsoft/kb3158991
- Platform: Microsoft
- Released: May 10, 2016
- Priority: Patch now (Closes CVE-2016-0189, exploited (CISA KEV, ransomware))
- CVEs: 1, exploited: 1, on CISA KEV: 1
- Vendor advisory: https://support.microsoft.com/help/3158991

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [Windows Server 2008 for 32-bit Systems Service Pack 2](https://patchblox.com/security/data/product/microsoft/windows-server-2008-for-32-bit-systems-service-pack-2.md) |  |  |
| [Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)](https://patchblox.com/security/data/product/microsoft/windows-server-2008-for-32-bit-systems-service-pack-2-server-core-installation.md) |  |  |
| [Windows Server 2008 for Itanium-Based Systems Service Pack 2](https://patchblox.com/security/data/product/microsoft/windows-server-2008-for-itanium-based-systems-service-pack-2.md) |  |  |
| [Windows Server 2008 for x64-based Systems Service Pack 2](https://patchblox.com/security/data/product/microsoft/windows-server-2008-for-x64-based-systems-service-pack-2.md) |  |  |
| [Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)](https://patchblox.com/security/data/product/microsoft/windows-server-2008-for-x64-based-systems-service-pack-2-server-core-installation.md) |  |  |
| [Windows Vista Service Pack 2](https://patchblox.com/security/data/product/microsoft/windows-vista-service-pack-2.md) |  |  |
| [Windows Vista x64 Edition Service Pack 2](https://patchblox.com/security/data/product/microsoft/windows-vista-x64-edition-service-pack-2.md) |  |  |

## CVEs this fix closes

| CVE | Priority | Component | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2016-0189](https://patchblox.com/security/data/cve/CVE-2016-0189.md) | Patch now | Internet Explorer | n/a | 0.9406 | CISA KEV, Ransomware |

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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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo