--- title: "CVE-2019-9511\n | Ubuntu" description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/CVE-2019-9511?format=md keywords: index, follow --- # CVE-2019-9511 Publication date 13 August 2019 Last updated 25 August 2025 --- Ubuntu priority **Medium** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) ## Cvss 3 Severity Score **7.5 · High** [Score breakdown](https://ubuntu.com/security/CVE-2019-9511?format=md#impact-score) Toggle side navigation ## Description Some HTTP/2 implementations are vulnerable to window size manipulation and stream prioritization manipulation, potentially leading to a denial of service. The attacker requests a large amount of data from a specified resource over multiple streams. They manipulate window size and stream priority to force the server to queue the data in 1-byte chunks. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both. [Read the notes from the security team](https://ubuntu.com/security/CVE-2019-9511?format=md#notes) ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | nghttp2 | 24.04 LTS noble | Not affected | | 23.10 mantic | Not affected | | 23.04 lunar | Not affected | | 22.10 kinetic | Not affected | | 22.04 LTS jammy | Not affected | | 21.10 impish | Not affected | | 21.04 hirsute | Not affected | | 20.10 groovy | Not affected | | 20.04 LTS focal | Not affected | | 19.10 eoan | Not affected | | 19.04 disco | Ignored end of life | | 18.10 cosmic | Ignored end of life | | 18.04 LTS bionic | Fixed 1.30.0-1ubuntu1+esm2 Ubuntu Pro | | 16.04 LTS xenial | Fixed 1.7.1-1ubuntu0.1~esm2 Ubuntu Pro | | 14.04 LTS trusty | Not in release | | nginx | 24.04 LTS noble | Fixed 1.16.1-0ubuntu1 | | 23.10 mantic | Fixed 1.16.1-0ubuntu1 | | 23.04 lunar | Fixed 1.16.1-0ubuntu1 | | 22.10 kinetic | Fixed 1.16.1-0ubuntu1 | | 22.04 LTS jammy | Fixed 1.16.1-0ubuntu1 | | 21.10 impish | Fixed 1.16.1-0ubuntu1 | | 21.04 hirsute | Fixed 1.16.1-0ubuntu1 | | 20.10 groovy | Fixed 1.16.1-0ubuntu1 | | 20.04 LTS focal | Fixed 1.16.1-0ubuntu1 | | 19.10 eoan | Fixed 1.16.1-0ubuntu1 | | 19.04 disco | Fixed 1.15.9-0ubuntu1.1 | | 18.10 cosmic | Ignored end of life | | 18.04 LTS bionic | Fixed 1.14.0-0ubuntu1.4 | | 16.04 LTS xenial | Fixed 1.10.3-0ubuntu0.16.04.4 | | 14.04 LTS trusty | Not affected | | nodejs | 24.04 LTS noble | Not affected | | 23.10 mantic | Not affected | | 23.04 lunar | Not affected | | 22.10 kinetic | Ignored end of life, was needs-triage | | 22.04 LTS jammy | Not affected | | 21.10 impish | Ignored end of life | | 21.04 hirsute | Ignored end of life | | 20.10 groovy | Ignored end of life | | 20.04 LTS focal | Not affected | | 18.04 LTS bionic | Ignored end of standard support, was needs-triage | | 16.04 LTS xenial | Ignored end of standard support, was needs-triage | | 14.04 LTS trusty | Ignored end of standard support | --- * [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) * [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses) * [Patch details](https://ubuntu.com/security/CVE-2019-9511?format=md#patch-details) ### Get expanded security coverage with Ubuntu Pro Reduce your average CVE exposure time from 98 days to 1 day with expanded CVE patching, ten-years security maintenance and optional support for the full stack of open-source applications. Free for personal use. [Get Ubuntu Pro](https://ubuntu.com/pro) [30-day free trial](https://ubuntu.com/pro/free-trial) ## Notes --- ### [sbeattie](https://launchpad.net/~sbeattie) nginx added http2 support in 1.9.5 nghttp2: nghttpd and nghttp are affected, libnghttp2 is not --- ### [mdeslaur](https://launchpad.net/~mdeslaur) nghttp2-server is in universe --- ### [sahnaseredini](https://launchpad.net/~sahnaseredini) nodejs patch is a version upgrade ### Patch details For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) | Package | Patch details | | --- | --- | | nginx | * Upstream: [94c5eb1](https://github.com/nginx/nginx/commit/94c5eb142e58a86f81eb1369fa6fcb96c2f23d6b) | ## Severity score breakdown CVSS version: CVSS v3.0 **Base score** 7.5 · High * Base metrics | Parameter | Value | | --- | --- | | Attack vector | Network | | Attack complexity | Low | | Privileges required | None | | User interaction | None | | Scope | Unchanged | | Confidentiality impact | None | | Integrity impact | None | | Availability impact | High | * Scores | Parameter | Value | | --- | --- | | Base score | 7.5 · High | | Exploitability score | - | | Impact score | - | **Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-9511) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2019-9511) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2019-9511) * [Debian](https://security-tracker.debian.org/tracker/CVE-2019-9511) ### Related Ubuntu Security Notices (USN) + [USN-4099-1](https://usn.ubuntu.com/USN-4099-1) + nginx vulnerabilities + 15 August 2019 + [USN-6754-1](https://usn.ubuntu.com/USN-6754-1) + nghttp2 vulnerabilities + 25 April 2024 ### Other references * * * * *