# CVE-2026-78445: Windows Services for NFS ONCRPC XDR Driver Remote Code Execution Vulnerability

CVE-2026-78445 is fixed in 12 products on 1 platform, first by KB5123099, released September 8, 2026. It is not reported as exploited. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/cve/CVE-2026-78445
- Priority: Urgent
- CVSS: 9.8 (Critical)
- EPSS: 0.0097
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation Less Likely
- Published: Sep 8, 2026
- Weakness: Use After Free
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78445

## Description

<p>Use after free in Windows Services for NFS ONCRPC XDR Driver allows an unauthorized attacker to execute code over a network.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Windows Server 2012 |  | [KB5123065](https://patchblox.com/security/data/fix/microsoft/kb5123065.md) | Sep 8, 2026 |
| Microsoft | Windows Server 2012 (Server Core installation) |  | [KB5123065](https://patchblox.com/security/data/fix/microsoft/kb5123065.md) | Sep 8, 2026 |
| Microsoft | Windows Server 2012 R2 |  | [KB5123066](https://patchblox.com/security/data/fix/microsoft/kb5123066.md) | Sep 8, 2026 |
| Microsoft | Windows Server 2012 R2 (Server Core installation) |  | [KB5123066](https://patchblox.com/security/data/fix/microsoft/kb5123066.md) | Sep 8, 2026 |
| Microsoft | Windows Server 2016 | 14393.9512 | [KB5123099](https://patchblox.com/security/data/fix/microsoft/kb5123099.md) | Sep 8, 2026 |
| Microsoft | Windows Server 2016 (Server Core installation) | 14393.9512 | [KB5123099](https://patchblox.com/security/data/fix/microsoft/kb5123099.md) | Sep 8, 2026 |
| Microsoft | Windows Server 2019 | 17763.9245 | [KB5122876](https://patchblox.com/security/data/fix/microsoft/kb5122876.md) | Sep 8, 2026 |
| Microsoft | Windows Server 2019 (Server Core installation) | 17763.9245 | [KB5122876](https://patchblox.com/security/data/fix/microsoft/kb5122876.md) | Sep 8, 2026 |
| Microsoft | Windows Server 2022 | 20348.5622 | [KB5122882](https://patchblox.com/security/data/fix/microsoft/kb5122882.md) | Sep 8, 2026 |
| Microsoft | Windows Server 2022 (Server Core installation) | 20348.5622 | [KB5122882](https://patchblox.com/security/data/fix/microsoft/kb5122882.md) | Sep 8, 2026 |
| Microsoft | Windows Server 2025 | 26100.33438 | [KB5122871](https://patchblox.com/security/data/fix/microsoft/kb5122871.md) | Sep 8, 2026 |
| Microsoft | Windows Server 2025 (Server Core installation) | 26100.33438 | [KB5122871](https://patchblox.com/security/data/fix/microsoft/kb5122871.md) | Sep 8, 2026 |

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Data as of 2026-11-07T12:40:37Z 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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