--- title: 'USN-8398-4: nginx vulnerability | Ubuntu security notices' 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/notices/USN-8398-4 --- 1. [Ubuntu Security Notices](https://ubuntu.com/security/notices) 2. USN-8398-4 --- # USN-8398-4: nginx vulnerability Publication date 2 July 2026 Overview nginx could be made to consume excessive resources if it received specially crafted network traffic. Releases [20.04 LTS](https://ubuntu.com/security/notices?release=focal) [18.04 LTS](https://ubuntu.com/security/notices?release=bionic) [16.04 LTS](https://ubuntu.com/security/notices?release=xenial) [14.04 LTS](https://ubuntu.com/security/notices?release=trusty) --- Open side navigation ## Packages * [nginx](https://ubuntu.com/security/cves?package=nginx) - small, powerful, scalable web/proxy server ## Details USN-8398-3 fixed a vulnerability in nginx. This update provides the corresponding fix for Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. Original advisory details: It was discovered that nginx incorrectly handled certain cookie headers in the HTTP/2 implementation. A remote attacker could possibly use this issue to cause nginx to consume excessive resources, resulting in a denial of service. ## Update instructions In general, a standard system update will make all the necessary changes. [Learn more about how to get the fixes.](https://ubuntu.com/security/cves/about#security) The problem can be corrected by updating your system to the following package versions: | Ubuntu Release | Package Version | | --- | --- | | 20.04 LTS focal | [nginx](https://launchpad.net/ubuntu/+source/nginx) –  1.18.0-0ubuntu1.7+esm3   Ubuntu Pro | | | | [nginx-common](https://launchpad.net/ubuntu/+source/nginx) –  1.18.0-0ubuntu1.7+esm3   Ubuntu Pro | | | | [nginx-core](https://launchpad.net/ubuntu/+source/nginx) –  1.18.0-0ubuntu1.7+esm3   Ubuntu Pro | | | | [nginx-extras](https://launchpad.net/ubuntu/+source/nginx) –  1.18.0-0ubuntu1.7+esm3   Ubuntu Pro | | | | [nginx-full](https://launchpad.net/ubuntu/+source/nginx) –  1.18.0-0ubuntu1.7+esm3   Ubuntu Pro | | | | [nginx-light](https://launchpad.net/ubuntu/+source/nginx) –  1.18.0-0ubuntu1.7+esm3   Ubuntu Pro | | | | 18.04 LTS bionic | [nginx](https://launchpad.net/ubuntu/+source/nginx) –  1.14.0-0ubuntu1.11+esm4   Ubuntu Pro | | | | [nginx-core](https://launchpad.net/ubuntu/+source/nginx) –  1.14.0-0ubuntu1.11+esm4   Ubuntu Pro | | | | [nginx-extras](https://launchpad.net/ubuntu/+source/nginx) –  1.14.0-0ubuntu1.11+esm4   Ubuntu Pro | | | | [nginx-full](https://launchpad.net/ubuntu/+source/nginx) –  1.14.0-0ubuntu1.11+esm4   Ubuntu Pro | | | | [nginx-light](https://launchpad.net/ubuntu/+source/nginx) –  1.14.0-0ubuntu1.11+esm4   Ubuntu Pro | | | | 16.04 LTS xenial | [nginx](https://launchpad.net/ubuntu/+source/nginx) –  1.10.3-0ubuntu0.16.04.5+esm9   Ubuntu Pro | | | | [nginx-common](https://launchpad.net/ubuntu/+source/nginx) –  1.10.3-0ubuntu0.16.04.5+esm9   Ubuntu Pro | | | | [nginx-core](https://launchpad.net/ubuntu/+source/nginx) –  1.10.3-0ubuntu0.16.04.5+esm9   Ubuntu Pro | | | | [nginx-extras](https://launchpad.net/ubuntu/+source/nginx) –  1.10.3-0ubuntu0.16.04.5+esm9   Ubuntu Pro | | | | [nginx-full](https://launchpad.net/ubuntu/+source/nginx) –  1.10.3-0ubuntu0.16.04.5+esm9   Ubuntu Pro | | | | [nginx-light](https://launchpad.net/ubuntu/+source/nginx) –  1.10.3-0ubuntu0.16.04.5+esm9   Ubuntu Pro | | | | 14.04 LTS trusty | [nginx](https://launchpad.net/ubuntu/+source/nginx) –  1.4.6-1ubuntu3.9+esm8   Ubuntu Pro | | | | [nginx-common](https://launchpad.net/ubuntu/+source/nginx) –  1.4.6-1ubuntu3.9+esm8   Ubuntu Pro | | | | [nginx-core](https://launchpad.net/ubuntu/+source/nginx) –  1.4.6-1ubuntu3.9+esm8   Ubuntu Pro | | | | [nginx-extras](https://launchpad.net/ubuntu/+source/nginx) –  1.4.6-1ubuntu3.9+esm8   Ubuntu Pro | | | | [nginx-full](https://launchpad.net/ubuntu/+source/nginx) –  1.4.6-1ubuntu3.9+esm8   Ubuntu Pro | | | | [nginx-light](https://launchpad.net/ubuntu/+source/nginx) –  1.4.6-1ubuntu3.9+esm8   Ubuntu Pro | | | --- ### Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. [Get Ubuntu Pro](https://ubuntu.com/pro) ## References * [CVE-2026-49975](https://ubuntu.com/security/CVE-2026-49975) ## Related notices * [USN-8571-1](https://ubuntu.com/security/notices/USN-8571-1) * [USN-8398-1](https://ubuntu.com/security/notices/USN-8398-1) * [USN-8398-3](https://ubuntu.com/security/notices/USN-8398-3) * [USN-8384-1](https://ubuntu.com/security/notices/USN-8384-1)