# KB5121610: September 2026 security update

KB5121610, released September 8, 2026, fixes 9 CVEs in Microsoft Exchange Server 2019 Cumulative Update 14. None of them is reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/fix/microsoft/kb5121610
- Platform: Microsoft
- Released: Sep 8, 2026
- Priority: High (Closes CVE-2026-69378, high severity)
- CVEs: 9, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://support.microsoft.com/help/5121610

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [Microsoft Exchange Server 2019 Cumulative Update 14](https://patchblox.com/security/data/product/microsoft/microsoft-exchange-server-2019-cumulative-update-14.md) |  |  |

## CVEs this fix closes

| CVE | Priority | Component | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2026-69378](https://patchblox.com/security/data/cve/CVE-2026-69378.md) | High | Microsoft Exchange Server | 7.5 | 0.0117 |  |
| [CVE-2026-69355](https://patchblox.com/security/data/cve/CVE-2026-69355.md) | High | Microsoft Exchange Server | 8.8 | 0.0091 |  |
| [CVE-2026-69641](https://patchblox.com/security/data/cve/CVE-2026-69641.md) | High | Microsoft Exchange Server | 9.1 | 0.0086 |  |
| [CVE-2026-69356](https://patchblox.com/security/data/cve/CVE-2026-69356.md) | High | Microsoft Exchange Server | 9.3 | 0.0076 |  |
| [CVE-2026-55007](https://patchblox.com/security/data/cve/CVE-2026-55007.md) | High | Microsoft Exchange Server | 8.1 | 0.0071 |  |
| [CVE-2026-69380](https://patchblox.com/security/data/cve/CVE-2026-69380.md) | High | Microsoft Exchange Server | 8.1 | 0.0069 |  |
| [CVE-2026-69361](https://patchblox.com/security/data/cve/CVE-2026-69361.md) | Routine | Microsoft Exchange Server | 6.5 | 0.0084 |  |
| [CVE-2026-69375](https://patchblox.com/security/data/cve/CVE-2026-69375.md) | Routine | Microsoft Exchange Server | 6.5 | 0.0064 |  |
| [CVE-2026-69382](https://patchblox.com/security/data/cve/CVE-2026-69382.md) | Routine | Microsoft Exchange Server | 5.9 | 0.0047 |  |

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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo