# KB4577352: September 2020 security update

KB4577352, released September 8, 2020, fixes 1 CVE across 4 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/kb4577352
- Platform: Microsoft
- Released: Sep 8, 2020
- Priority: Urgent (Closes CVE-2020-16875, rated Critical)
- CVEs: 1, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://support.microsoft.com/help/4577352

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [Microsoft Exchange Server 2016 Cumulative Update 16](https://patchblox.com/security/data/product/microsoft/microsoft-exchange-server-2016-cumulative-update-16.md) |  |  |
| [Microsoft Exchange Server 2016 Cumulative Update 17](https://patchblox.com/security/data/product/microsoft/microsoft-exchange-server-2016-cumulative-update-17.md) |  |  |
| [Microsoft Exchange Server 2019 Cumulative Update 5](https://patchblox.com/security/data/product/microsoft/microsoft-exchange-server-2019-cumulative-update-5.md) |  |  |
| [Microsoft Exchange Server 2019 Cumulative Update 6](https://patchblox.com/security/data/product/microsoft/microsoft-exchange-server-2019-cumulative-update-6.md) |  |  |

## CVEs this fix closes

| CVE | Priority | Component | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2020-16875](https://patchblox.com/security/data/cve/CVE-2020-16875.md) | Urgent | Microsoft Exchange Server | 8.4 | 0.4650 |  |

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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo