# KB5004238: July 2021 cumulative update for Windows 10 1607 KB5004238, released July 13, 2021, fixes 59 CVEs across 4 products. 3 of them are being exploited (CVE-2021-34448); 3 on CISA KEV. Patch Radar priority: Patch now. - Web page: https://patchblox.com/security/fix/microsoft/kb5004238 - Platform: Microsoft - Released: Jul 13, 2021 - Priority: Patch now (Closes CVE-2021-34448, exploited (CISA KEV)) - CVEs: 59, exploited: 3, on CISA KEV: 3 - Vendor advisory: https://support.microsoft.com/help/5004238 ## Applies to | Product | Release | Fixed in | |---|---|---| | [Windows 10 Version 1607 for 32-bit Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-1607-for-32-bit-systems.md) | | 14393.4530 | | [Windows 10 Version 1607 for x64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-1607-for-x64-based-systems.md) | | 14393.4530 | | [Windows Server 2016](https://patchblox.com/security/data/product/microsoft/windows-server-2016.md) | | 14393.4530 | | [Windows Server 2016 (Server Core installation)](https://patchblox.com/security/data/product/microsoft/windows-server-2016-server-core-installation.md) | | 14393.4530 | ## 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-2021-34494](https://patchblox.com/security/data/cve/CVE-2021-34494.md) | Urgent | Role: DNS Server | 8.8 | 0.0405 | | | [CVE-2021-33780](https://patchblox.com/security/data/cve/CVE-2021-33780.md) | Urgent | Role: DNS Server | 8.8 | 0.0271 | More likely | | [CVE-2021-34439](https://patchblox.com/security/data/cve/CVE-2021-34439.md) | Urgent | Microsoft Windows Media Foundation | 7.8 | 0.0267 | | | [CVE-2021-34458](https://patchblox.com/security/data/cve/CVE-2021-34458.md) | Urgent | Windows Kernel | 9.9 | 0.0263 | | | [CVE-2021-34497](https://patchblox.com/security/data/cve/CVE-2021-34497.md) | Urgent | Windows MSHTML Platform | 6.8 | 0.0215 | | | [CVE-2020-17049](https://patchblox.com/security/data/cve/CVE-2020-17049.md) | High | Microsoft Windows | 7.2 | 0.1379 | | | [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-2021-34442](https://patchblox.com/security/data/cve/CVE-2021-34442.md) | High | Role: DNS Server | 8.8 | 0.0317 | | | [CVE-2021-33758](https://patchblox.com/security/data/cve/CVE-2021-33758.md) | High | Role: Windows Hyper-V | 7.7 | 0.0287 | | | [CVE-2021-34492](https://patchblox.com/security/data/cve/CVE-2021-34492.md) | High | Windows PFX Encryption | 8.1 | 0.0247 | Disclosed | | [CVE-2021-33779](https://patchblox.com/security/data/cve/CVE-2021-33779.md) | High | Active Directory Federation Services | 8.1 | 0.0244 | 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-2021-34525](https://patchblox.com/security/data/cve/CVE-2021-34525.md) | High | Role: DNS Server | 8.8 | 0.0225 | | | [CVE-2021-34441](https://patchblox.com/security/data/cve/CVE-2021-34441.md) | High | Microsoft Windows Media Foundation | 7.8 | 0.0222 | | | [CVE-2021-33786](https://patchblox.com/security/data/cve/CVE-2021-33786.md) | High | Windows Local Security Authority Subsystem Service (LSASS) | 8.1 | 0.0212 | | | [CVE-2021-34446](https://patchblox.com/security/data/cve/CVE-2021-34446.md) | High | Windows HTML Platform | 8.0 | 0.0205 | | | [CVE-2021-33746](https://patchblox.com/security/data/cve/CVE-2021-33746.md) | High | Microsoft Windows DNS | 8.0 | 0.0200 | | | [CVE-2021-33754](https://patchblox.com/security/data/cve/CVE-2021-33754.md) | High | Microsoft Windows DNS | 8.0 | 0.0198 | | | [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-2021-33751](https://patchblox.com/security/data/cve/CVE-2021-33751.md) | High | Windows Storage Spaces Controller | 7.0 | 0.0082 | | | [CVE-2021-34514](https://patchblox.com/security/data/cve/CVE-2021-34514.md) | High | Windows Kernel | 7.8 | 0.0070 | | | [CVE-2021-33759](https://patchblox.com/security/data/cve/CVE-2021-33759.md) | High | Windows Desktop Bridge | 7.8 | 0.0065 | | | [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-2021-34444](https://patchblox.com/security/data/cve/CVE-2021-34444.md) | Routine | Role: DNS Server | 6.5 | 0.0346 | | | [CVE-2021-34507](https://patchblox.com/security/data/cve/CVE-2021-34507.md) | Routine | Windows Remote Assistance | 6.5 | 0.0326 | | | [CVE-2021-33764](https://patchblox.com/security/data/cve/CVE-2021-33764.md) | Routine | Windows Key Distribution Center | 5.9 | 0.0305 | | | [CVE-2021-33757](https://patchblox.com/security/data/cve/CVE-2021-33757.md) | Routine | Windows Security Account Manager | 5.3 | 0.0295 | | | [CVE-2021-33745](https://patchblox.com/security/data/cve/CVE-2021-33745.md) | Routine | Role: DNS Server | 6.5 | 0.0287 | | | [CVE-2021-34499](https://patchblox.com/security/data/cve/CVE-2021-34499.md) | Routine | Microsoft Windows DNS | 6.5 | 0.0287 | | | [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-2021-34509](https://patchblox.com/security/data/cve/CVE-2021-34509.md) | Routine | Windows Storage Spaces Controller | 5.5 | 0.0095 | | | [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 | | --- 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