# KB5004249: July 2021 cumulative update for Windows 10 1507

KB5004249, released July 13, 2021, fixes 42 CVEs across 2 products. 3 of them are being exploited (CVE-2021-34448); 3 on CISA KEV. Patch Radar priority: Patch now. The product is no longer supported.

- Web page: https://patchblox.com/security/fix/microsoft/kb5004249
- Platform: Microsoft
- Released: Jul 13, 2021
- Priority: Patch now (Closes CVE-2021-34448, exploited (CISA KEV))
- CVEs: 42, exploited: 3, on CISA KEV: 3
- Vendor advisory: https://support.microsoft.com/help/5004249

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [Windows 10 for 32-bit Systems](https://patchblox.com/security/data/product/microsoft/windows-10-for-32-bit-systems.md) |  | 10240.19003 |
| [Windows 10 for x64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-for-x64-based-systems.md) |  | 10240.19003 |

## CVEs this fix closes

| CVE | Priority | Component | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2021-34448](https://patchblox.com/security/data/cve/CVE-2021-34448.md) | Patch now | Microsoft Scripting Engine | 6.8 | 0.4006 | CISA KEV |
| [CVE-2021-33771](https://patchblox.com/security/data/cve/CVE-2021-33771.md) | Patch now | Windows Kernel | 7.8 | 0.1017 | CISA KEV |
| [CVE-2021-31979](https://patchblox.com/security/data/cve/CVE-2021-31979.md) | Patch now | Windows Kernel | 7.8 | 0.0454 | CISA KEV |
| [CVE-2021-33740](https://patchblox.com/security/data/cve/CVE-2021-33740.md) | Urgent | Microsoft Windows Codecs Library | 7.8 | 0.0276 |  |
| [CVE-2021-34439](https://patchblox.com/security/data/cve/CVE-2021-34439.md) | Urgent | Microsoft Windows Media Foundation | 7.8 | 0.0267 |  |
| [CVE-2021-34497](https://patchblox.com/security/data/cve/CVE-2021-34497.md) | Urgent | Windows MSHTML Platform | 6.8 | 0.0215 |  |
| [CVE-2021-31183](https://patchblox.com/security/data/cve/CVE-2021-31183.md) | High | Windows TCP/IP | 7.5 | 0.0384 |  |
| [CVE-2021-34504](https://patchblox.com/security/data/cve/CVE-2021-34504.md) | High | Windows Address Book | 7.8 | 0.0347 |  |
| [CVE-2021-33788](https://patchblox.com/security/data/cve/CVE-2021-33788.md) | High | Windows Local Security Authority Subsystem Service (LSASS) | 7.5 | 0.0328 |  |
| [CVE-2021-34476](https://patchblox.com/security/data/cve/CVE-2021-34476.md) | High | Common Internet File System | 7.5 | 0.0328 |  |
| [CVE-2021-34492](https://patchblox.com/security/data/cve/CVE-2021-34492.md) | High | Windows PFX Encryption | 8.1 | 0.0247 | Disclosed |
| [CVE-2021-33749](https://patchblox.com/security/data/cve/CVE-2021-33749.md) | High | Role: DNS Server | 8.8 | 0.0242 |  |
| [CVE-2021-33750](https://patchblox.com/security/data/cve/CVE-2021-33750.md) | High | Role: DNS Server | 8.8 | 0.0242 |  |
| [CVE-2021-33752](https://patchblox.com/security/data/cve/CVE-2021-33752.md) | High | Role: DNS Server | 8.8 | 0.0242 |  |
| [CVE-2021-33756](https://patchblox.com/security/data/cve/CVE-2021-33756.md) | High | Role: DNS Server | 8.8 | 0.0241 |  |
| [CVE-2021-34441](https://patchblox.com/security/data/cve/CVE-2021-34441.md) | High | Microsoft Windows Media Foundation | 7.8 | 0.0222 |  |
| [CVE-2021-34446](https://patchblox.com/security/data/cve/CVE-2021-34446.md) | High | Windows HTML Platform | 8.0 | 0.0205 |  |
| [CVE-2021-34516](https://patchblox.com/security/data/cve/CVE-2021-34516.md) | High | Windows Win32K | 7.8 | 0.0130 |  |
| [CVE-2021-34498](https://patchblox.com/security/data/cve/CVE-2021-34498.md) | High | Microsoft Graphics Component | 7.8 | 0.0106 |  |
| [CVE-2021-34512](https://patchblox.com/security/data/cve/CVE-2021-34512.md) | High | Windows Storage Spaces Controller | 7.8 | 0.0106 |  |
| [CVE-2021-34462](https://patchblox.com/security/data/cve/CVE-2021-34462.md) | High | Windows AppX Deployment Extensions | 7.0 | 0.0085 |  |
| [CVE-2021-34514](https://patchblox.com/security/data/cve/CVE-2021-34514.md) | High | Windows Kernel | 7.8 | 0.0070 |  |
| [CVE-2021-33773](https://patchblox.com/security/data/cve/CVE-2021-33773.md) | High | Windows Remote Access Connection Manager | 7.8 | 0.0064 |  |
| [CVE-2021-33761](https://patchblox.com/security/data/cve/CVE-2021-33761.md) | High | Windows Remote Access Connection Manager | 7.8 | 0.0061 |  |
| [CVE-2021-34511](https://patchblox.com/security/data/cve/CVE-2021-34511.md) | High | Windows Installer | 7.8 | 0.0057 |  |
| [CVE-2021-34460](https://patchblox.com/security/data/cve/CVE-2021-34460.md) | High | Windows Storage Spaces Controller | 7.8 | 0.0056 |  |
| [CVE-2021-34456](https://patchblox.com/security/data/cve/CVE-2021-34456.md) | High | Windows Remote Access Connection Manager | 7.8 | 0.0056 |  |
| [CVE-2021-34455](https://patchblox.com/security/data/cve/CVE-2021-34455.md) | High | Windows File History Service | 7.8 | 0.0053 |  |
| [CVE-2021-34459](https://patchblox.com/security/data/cve/CVE-2021-34459.md) | High | Windows AppContainer | 7.8 | 0.0053 |  |
| [CVE-2021-34507](https://patchblox.com/security/data/cve/CVE-2021-34507.md) | Routine | Windows Remote Assistance | 6.5 | 0.0326 |  |
| [CVE-2021-33757](https://patchblox.com/security/data/cve/CVE-2021-33757.md) | Routine | Windows Security Account Manager | 5.3 | 0.0295 |  |
| [CVE-2021-33783](https://patchblox.com/security/data/cve/CVE-2021-33783.md) | Routine | Windows SMB | 6.5 | 0.0277 |  |
| [CVE-2021-33782](https://patchblox.com/security/data/cve/CVE-2021-33782.md) | Routine | Windows Authenticode | 5.5 | 0.0225 |  |
| [CVE-2021-34447](https://patchblox.com/security/data/cve/CVE-2021-34447.md) | Routine | Windows MSHTML Platform | 6.8 | 0.0205 |  |
| [CVE-2021-34496](https://patchblox.com/security/data/cve/CVE-2021-34496.md) | Routine | Microsoft Graphics Component | 5.5 | 0.0204 |  |
| [CVE-2021-34491](https://patchblox.com/security/data/cve/CVE-2021-34491.md) | Routine | Windows Win32K | 5.5 | 0.0097 |  |
| [CVE-2021-33763](https://patchblox.com/security/data/cve/CVE-2021-33763.md) | Routine | Windows Remote Access Connection Manager | 5.5 | 0.0088 |  |
| [CVE-2021-34440](https://patchblox.com/security/data/cve/CVE-2021-34440.md) | Routine | Microsoft Graphics Component | 5.5 | 0.0088 |  |
| [CVE-2021-34454](https://patchblox.com/security/data/cve/CVE-2021-34454.md) | Routine | Windows Shell | 5.5 | 0.0087 |  |
| [CVE-2021-34457](https://patchblox.com/security/data/cve/CVE-2021-34457.md) | Routine | Windows Remote Access Connection Manager | 5.5 | 0.0087 |  |
| [CVE-2021-33765](https://patchblox.com/security/data/cve/CVE-2021-33765.md) | Routine | Windows Installer | 6.2 | 0.0073 |  |
| [CVE-2021-34493](https://patchblox.com/security/data/cve/CVE-2021-34493.md) | Routine | Windows Partition Management Driver | 6.7 | 0.0065 |  |

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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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