--- title: 'USN-8474-1: NSD vulnerabilities | 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-8474-1 --- 1. [Ubuntu Security Notices](https://ubuntu.com/security/notices) 2. USN-8474-1 --- # USN-8474-1: NSD vulnerabilities Publication date 25 June 2026 Overview NSD could be made to crash or run programs if it received specially crafted network traffic. Releases [26.04 LTS](https://ubuntu.com/security/notices?release=resolute) [24.04 LTS](https://ubuntu.com/security/notices?release=noble) [22.04 LTS](https://ubuntu.com/security/notices?release=jammy) [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) --- Open side navigation ## Packages * [nsd](https://ubuntu.com/security/cves?package=nsd) - Several security issues were fixed in NSD, including a stack-based buffer overflow in APL resource record handling. ## Details It was discovered that NSD incorrectly handled APL resource records with an address length larger than permitted for the address family. A remote attacker could use this to cause a stack-based buffer overflow when the zone is written to disk, potentially executing arbitrary code with the privileges of the NSD server. ([CVE-2026-12246](https://ubuntu.com/security/CVE-2026-12246)) It was discovered that NSD incorrectly handled SVCB resource records. A remote attacker could use this to cause a heap overflow, potentially executing arbitrary code with the privileges of the NSD server. This issue only affected Ubuntu 26.04 LTS. ([CVE-2026-12244](https://ubuntu.com/security/CVE-2026-12244)) It was discovered that NSD had a use-after-free vulnerability in TLS connection error logging. A remote attacker could use this to cause a denial of service by crashing the server process. This issue only affected Ubuntu 26.04 LTS. ( --- Show more ## 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 | | --- | --- | | 26.04 LTS resolute | [nsd](https://launchpad.net/ubuntu/+source/nsd) –  4.14.0-1ubuntu0.1~esm1   Ubuntu Pro | | | | 24.04 LTS noble | [nsd](https://launchpad.net/ubuntu/+source/nsd) –  4.8.0-1ubuntu0.1~esm1   Ubuntu Pro | | | | 22.04 LTS jammy | [nsd](https://launchpad.net/ubuntu/+source/nsd) –  4.3.9-1ubuntu0.1~esm1   Ubuntu Pro | | | | 20.04 LTS focal | [nsd](https://launchpad.net/ubuntu/+source/nsd) –  4.1.26-1ubuntu0.1~esm1   Ubuntu Pro | | | | 18.04 LTS bionic | [nsd](https://launchpad.net/ubuntu/+source/nsd) –  4.1.17-1ubuntu0.1~esm1   Ubuntu Pro | | | | 16.04 LTS xenial | [nsd](https://launchpad.net/ubuntu/+source/nsd) –  4.1.7-1ubuntu0.1~esm1 | | | | [nsd3](https://launchpad.net/ubuntu/+source/nsd) –  4.1.7-1ubuntu0.1~esm1 | | | --- ### 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-2026-12490](https://ubuntu.com/security/CVE-2026-12490) * [CVE-2026-12246](https://ubuntu.com/security/CVE-2026-12246) * [CVE-2026-12245](https://ubuntu.com/security/CVE-2026-12245) * [CVE-2026-12244](https://ubuntu.com/security/CVE-2026-12244)