# CVE-2026-78464: Windows MIDI Service Module Elevation of Privileges Vulnerability

CVE-2026-78464 is fixed in 6 products on 1 platform, first by KB5124008, released September 8, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-78464
- Priority: High
- CVSS: 7.0 (Important)
- EPSS: 0.0020
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation Less Likely
- Published: Sep 8, 2026
- Weakness: Time-of-check Time-of-use (TOCTOU) Race Condition
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78464

## Description

<p>Time-of-check time-of-use (toctou) race condition in Windows MIDI Service Module allows an authorized attacker to elevate privileges locally.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Windows 11 Version 24H2 for ARM64-based Systems |  | [KB5124008](https://patchblox.com/security/data/fix/microsoft/kb5124008.md) | Sep 8, 2026 |
| Microsoft | Windows 11 Version 24H2 for x64-based Systems |  | [KB5124008](https://patchblox.com/security/data/fix/microsoft/kb5124008.md) | Sep 8, 2026 |
| Microsoft | Windows 11 Version 25H2 for ARM64-based Systems |  | [KB5124008](https://patchblox.com/security/data/fix/microsoft/kb5124008.md) | Sep 8, 2026 |
| Microsoft | Windows 11 Version 25H2 for x64-based Systems |  | [KB5124008](https://patchblox.com/security/data/fix/microsoft/kb5124008.md) | Sep 8, 2026 |
| Microsoft | Windows 11 Version 26H1 for ARM64-based Systems | 28000.2954 | [KB5124012](https://patchblox.com/security/data/fix/microsoft/kb5124012.md) | Sep 8, 2026 |
| Microsoft | Windows 11 version 26H1 for x64-based Systems | 28000.2954 | [KB5124012](https://patchblox.com/security/data/fix/microsoft/kb5124012.md) | Sep 8, 2026 |

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Data as of 2026-11-07T18:46:35Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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