# CVE-2019-0865: SymCrypt Denial of Service Vulnerability

CVE-2019-0865 is fixed in 18 products on 1 platform, first by KB4507450, released July 9, 2019. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2019-0865
- Priority: High
- CVSS: 7.5 (Important)
- EPSS: 0.0450
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: yes
- Vendor exploitability assessment: Exploitation Less Likely
- Published: Jul 9, 2019
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2019-0865

## Description

<p>A denial of service vulnerability exists when SymCrypt improperly handles a specially crafted digital signature.</p> <p>An attacker could exploit the vulnerability by creating a specially crafted connection or message.</p> <p>The security update addresses the vulnerability by correcting the way SymCrypt handles digital signatures.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Windows 10 Version 1703 for 32-bit Systems | 15063.1928 | [KB4507450](https://patchblox.com/security/data/fix/microsoft/kb4507450.md) | Jul 9, 2019 |
| Microsoft | Windows 10 Version 1703 for x64-based Systems | 15063.1928 | [KB4507450](https://patchblox.com/security/data/fix/microsoft/kb4507450.md) | Jul 9, 2019 |
| Microsoft | Windows 10 Version 1709 for 32-bit Systems | 16299.1268 | [KB4507455](https://patchblox.com/security/data/fix/microsoft/kb4507455.md) | Jul 9, 2019 |
| Microsoft | Windows 10 Version 1709 for ARM64-based Systems | 16299.1268 | [KB4507455](https://patchblox.com/security/data/fix/microsoft/kb4507455.md) | Jul 9, 2019 |
| Microsoft | Windows 10 Version 1709 for x64-based Systems | 16299.1268 | [KB4507455](https://patchblox.com/security/data/fix/microsoft/kb4507455.md) | Jul 9, 2019 |
| Microsoft | Windows 10 Version 1803 for 32-bit Systems | 17134.885 | [KB4507435](https://patchblox.com/security/data/fix/microsoft/kb4507435.md) | Jul 9, 2019 |
| Microsoft | Windows 10 Version 1803 for ARM64-based Systems | 17134.885 | [KB4507435](https://patchblox.com/security/data/fix/microsoft/kb4507435.md) | Jul 9, 2019 |
| Microsoft | Windows 10 Version 1803 for x64-based Systems | 17134.885 | [KB4507435](https://patchblox.com/security/data/fix/microsoft/kb4507435.md) | Jul 9, 2019 |
| Microsoft | Windows 10 Version 1809 for 32-bit Systems | 17763.615 | [KB4507469](https://patchblox.com/security/data/fix/microsoft/kb4507469.md) | Jul 9, 2019 |
| Microsoft | Windows 10 Version 1809 for ARM64-based Systems | 17763.615 | [KB4507469](https://patchblox.com/security/data/fix/microsoft/kb4507469.md) | Jul 9, 2019 |
| Microsoft | Windows 10 Version 1809 for x64-based Systems | 17763.615 | [KB4507469](https://patchblox.com/security/data/fix/microsoft/kb4507469.md) | Jul 9, 2019 |
| Microsoft | Windows 10 Version 1903 for 32-bit Systems | 18362.239 | [KB4507453](https://patchblox.com/security/data/fix/microsoft/kb4507453.md) | Jul 9, 2019 |
| Microsoft | Windows 10 Version 1903 for ARM64-based Systems | 18362.239 | [KB4507453](https://patchblox.com/security/data/fix/microsoft/kb4507453.md) | Jul 9, 2019 |
| Microsoft | Windows 10 Version 1903 for x64-based Systems | 18362.239 | [KB4507453](https://patchblox.com/security/data/fix/microsoft/kb4507453.md) | Jul 9, 2019 |
| Microsoft | Windows Server 2019 | 17763.615 | [KB4507469](https://patchblox.com/security/data/fix/microsoft/kb4507469.md) | Jul 9, 2019 |
| Microsoft | Windows Server 2019 (Server Core installation) | 17763.615 | [KB4507469](https://patchblox.com/security/data/fix/microsoft/kb4507469.md) | Jul 9, 2019 |
| Microsoft | Windows Server, version 1803  (Server Core Installation) | 17134.885 | [KB4507435](https://patchblox.com/security/data/fix/microsoft/kb4507435.md) | Jul 9, 2019 |
| Microsoft | Windows Server, version 1903 (Server Core installation) | 18362.239 | [KB4507453](https://patchblox.com/security/data/fix/microsoft/kb4507453.md) | Jul 9, 2019 |

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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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