# CVE-2019-9518: HTTP/2 Server Denial of Service Vulnerability CVE-2019-9518 is fixed in 31 products on 2 platforms, first by libnetty-java 1:4.1.7-4ubuntu0.1+esm1, released August 12, 2019. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2019-9518 - Priority: High - CVSS: 7.5 (Important) - EPSS: 0.2545 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Vendor exploitability assessment: Exploitation Less Likely - Published: Aug 12, 2019 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2019-9518 ## Description

A denial of service vulnerability exists in the HTTP/2 protocol stack (HTTP.sys) when HTTP.sys improperly parses specially crafted HTTP/2 requests. An attacker who successfully exploited the vulnerability could create a denial of service condition, causing the target system to become unresponsive.

To exploit this vulnerability, an unauthenticated attacker could send a specially crafted HTTP packet to a target system, causing the affected system to become nonresponsive.

The update addresses the vulnerability by modifying how the Windows HTTP protocol stack handles HTTP/2 requests. Note that the denial of service vulnerability would not allow an attacker to execute code or to elevate user rights.

## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Microsoft | Windows 10 Version 1607 for 32-bit Systems | 14393.3144 | [KB4512517](https://patchblox.com/security/data/fix/microsoft/kb4512517.md) | Aug 13, 2019 | | Microsoft | Windows 10 Version 1607 for x64-based Systems | 14393.3144 | [KB4512517](https://patchblox.com/security/data/fix/microsoft/kb4512517.md) | Aug 13, 2019 | | Microsoft | Windows 10 Version 1703 for 32-bit Systems | 15063.1988 | [KB4512507](https://patchblox.com/security/data/fix/microsoft/kb4512507.md) | Aug 13, 2019 | | Microsoft | Windows 10 Version 1703 for x64-based Systems | 15063.1988 | [KB4512507](https://patchblox.com/security/data/fix/microsoft/kb4512507.md) | Aug 13, 2019 | | Microsoft | Windows 10 Version 1709 for 32-bit Systems | 16299.1331 | [KB4512516](https://patchblox.com/security/data/fix/microsoft/kb4512516.md) | Aug 13, 2019 | | Microsoft | Windows 10 Version 1709 for ARM64-based Systems | 16299.1331 | [KB4512516](https://patchblox.com/security/data/fix/microsoft/kb4512516.md) | Aug 13, 2019 | | Microsoft | Windows 10 Version 1709 for x64-based Systems | 16299.1331 | [KB4512516](https://patchblox.com/security/data/fix/microsoft/kb4512516.md) | Aug 13, 2019 | | Microsoft | Windows 10 Version 1803 for 32-bit Systems | 17134.950 | [KB4512501](https://patchblox.com/security/data/fix/microsoft/kb4512501.md) | Aug 13, 2019 | | Microsoft | Windows 10 Version 1803 for ARM64-based Systems | 17134.950 | [KB4512501](https://patchblox.com/security/data/fix/microsoft/kb4512501.md) | Aug 13, 2019 | | Microsoft | Windows 10 Version 1803 for x64-based Systems | 17134.950 | [KB4512501](https://patchblox.com/security/data/fix/microsoft/kb4512501.md) | Aug 13, 2019 | | Microsoft | Windows 10 Version 1809 for 32-bit Systems | 17763.678 | [KB4511553](https://patchblox.com/security/data/fix/microsoft/kb4511553.md) | Aug 13, 2019 | | Microsoft | Windows 10 Version 1809 for ARM64-based Systems | 17763.678 | [KB4511553](https://patchblox.com/security/data/fix/microsoft/kb4511553.md) | Aug 13, 2019 | | Microsoft | Windows 10 Version 1809 for x64-based Systems | 17763.678 | [KB4511553](https://patchblox.com/security/data/fix/microsoft/kb4511553.md) | Aug 13, 2019 | | Microsoft | Windows 10 Version 1903 for 32-bit Systems | 18362.295 | [KB4512508](https://patchblox.com/security/data/fix/microsoft/kb4512508.md) | Aug 13, 2019 | | Microsoft | Windows 10 Version 1903 for ARM64-based Systems | 18362.295 | [KB4512508](https://patchblox.com/security/data/fix/microsoft/kb4512508.md) | Aug 13, 2019 | | Microsoft | Windows 10 Version 1903 for x64-based Systems | 18362.295 | [KB4512508](https://patchblox.com/security/data/fix/microsoft/kb4512508.md) | Aug 13, 2019 | | Microsoft | Windows 10 for 32-bit Systems | 10240.18305 | [KB4512497](https://patchblox.com/security/data/fix/microsoft/kb4512497.md) | Aug 13, 2019 | | Microsoft | Windows 10 for x64-based Systems | 10240.18305 | [KB4512497](https://patchblox.com/security/data/fix/microsoft/kb4512497.md) | Aug 13, 2019 | | Microsoft | Windows Server 2016 | 14393.3144 | [KB4512517](https://patchblox.com/security/data/fix/microsoft/kb4512517.md) | Aug 13, 2019 | | Microsoft | Windows Server 2016 (Server Core installation) | 14393.3144 | [KB4512517](https://patchblox.com/security/data/fix/microsoft/kb4512517.md) | Aug 13, 2019 | | Microsoft | Windows Server 2019 | 17763.678 | [KB4511553](https://patchblox.com/security/data/fix/microsoft/kb4511553.md) | Aug 13, 2019 | | Microsoft | Windows Server 2019 (Server Core installation) | 17763.678 | [KB4511553](https://patchblox.com/security/data/fix/microsoft/kb4511553.md) | Aug 13, 2019 | | Microsoft | Windows Server, version 1803 (Server Core Installation) | 17134.950 | [KB4512501](https://patchblox.com/security/data/fix/microsoft/kb4512501.md) | Aug 13, 2019 | | Microsoft | Windows Server, version 1903 (Server Core installation) | 18362.295 | [KB4512508](https://patchblox.com/security/data/fix/microsoft/kb4512508.md) | Aug 13, 2019 | | Linux | libnetty-java Ubuntu 18.04.6 LTS (bionic) | 1:4.1.7-4ubuntu0.1+esm1 | [libnetty-java 1:4.1.7-4ubuntu0.1+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libnetty-java-1-4.1.7-4ubuntu0.1-esm1.md) | Aug 12, 2019 | | Linux | nodejs RHEL 8 | 1:10.16.3-2.module+el8.0.0+4214+49953fda | [RHSA-2019:2925](https://patchblox.com/security/data/fix/linux/rhsa-2019-2925.md) | Sep 30, 2019 | | Linux | nodejs ol 8 | 1:10.14.1-1.module+el8.0.0+5349+4d6b561f | [ELSA-2019-2925](https://patchblox.com/security/data/fix/linux/elsa-2019-2925.md) | Sep 30, 2019 | | Linux | nodejs-devel RHEL 8 | 1:10.16.3-2.module+el8.0.0+4214+49953fda | [RHSA-2019:2925](https://patchblox.com/security/data/fix/linux/rhsa-2019-2925.md) | Sep 30, 2019 | | Linux | nodejs-devel ol 8 | 1:10.14.1-1.module+el8.0.0+5349+4d6b561f | [ELSA-2019-2925](https://patchblox.com/security/data/fix/linux/elsa-2019-2925.md) | Sep 30, 2019 | | Linux | nodejs-docs RHEL 8 | 1:10.16.3-2.module+el8.0.0+4214+49953fda | [RHSA-2019:2925](https://patchblox.com/security/data/fix/linux/rhsa-2019-2925.md) | Sep 30, 2019 | | Linux | nodejs-docs ol 8 | 1:10.14.1-1.module+el8.0.0+5349+4d6b561f | [ELSA-2019-2925](https://patchblox.com/security/data/fix/linux/elsa-2019-2925.md) | Sep 30, 2019 | | Linux | nodejs-nodemon RHEL 8 | 0:1.18.3-1.module+el8+2632+6c5111ed | [RHSA-2019:2925](https://patchblox.com/security/data/fix/linux/rhsa-2019-2925.md) | Sep 30, 2019 | | Linux | nodejs-nodemon ol 8 | 0:1.18.3-1.module+el8.0.0+5349+4d6b561f | [ELSA-2019-2925](https://patchblox.com/security/data/fix/linux/elsa-2019-2925.md) | Sep 30, 2019 | | Linux | nodejs-packaging RHEL 8 | 0:17-3.module+el8+2873+aa7dfd9a | [RHSA-2019:2925](https://patchblox.com/security/data/fix/linux/rhsa-2019-2925.md) | Sep 30, 2019 | | Linux | nodejs-packaging ol 8 | 0:17-3.module+el8.0.0+5349+4d6b561f | [ELSA-2019-2925](https://patchblox.com/security/data/fix/linux/elsa-2019-2925.md) | Sep 30, 2019 | | Linux | npm RHEL 8 | 1:6.9.0-1.10.16.3.2.module+el8.0.0+4214+49953fda | [RHSA-2019:2925](https://patchblox.com/security/data/fix/linux/rhsa-2019-2925.md) | Sep 30, 2019 | | Linux | npm ol 8 | 1:6.4.1-1.10.14.1.1.module+el8.0.0+5349+4d6b561f | [ELSA-2019-2925](https://patchblox.com/security/data/fix/linux/elsa-2019-2925.md) | Sep 30, 2019 | --- Data as of 2026-11-07T18:46:35Z UTC. 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