--- title: 'USN-8302-1: NLTK 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-8302-1 --- 1. [Ubuntu Security Notices](https://ubuntu.com/security/notices) 2. USN-8302-1 --- # USN-8302-1: NLTK vulnerabilities Publication date 25 May 2026 Overview Several security issues were fixed in NLTK. 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) [14.04 LTS](https://ubuntu.com/security/notices?release=trusty) --- Open side navigation ## Packages * [nltk](https://ubuntu.com/security/cves?package=nltk) - Natural Language Toolkit ## Details It was discovered that NLTK incorrectly validated file paths when opening files using the nltk.util module. An attacker could possibly use this issue to obtain sensitive information. ([CVE-2026-0846](https://ubuntu.com/security/CVE-2026-0846)) It was discovered that NLTK incorrectly validated file paths in multiple CorpusReader classes. An attacker could possibly use this issue to obtain sensitive information. ([CVE-2026-0847](https://ubuntu.com/security/CVE-2026-0847)) It was discovered that NLTK did not properly validate external Java archive files loaded by StanfordSegmenter. An attacker could possibly use this issue to execute arbitrary code. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. ([CVE-2026-0848](https://ubuntu.com/security/CVE-2026-0848)) It was discovered that NLTK's WordNet browser application incorrectly handled user-supplied input. An attacker... --- 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 | [python3-nltk](https://launchpad.net/ubuntu/+source/nltk) –  3.9.2-1ubuntu0.1~esm2   Ubuntu Pro | | | | 24.04 LTS noble | [python3-nltk](https://launchpad.net/ubuntu/+source/nltk) –  3.8.1-1ubuntu0.1~esm2   Ubuntu Pro | | | | 22.04 LTS jammy | [python3-nltk](https://launchpad.net/ubuntu/+source/nltk) –  3.7-1ubuntu0.1~esm2   Ubuntu Pro | | | | 20.04 LTS focal | [python3-nltk](https://launchpad.net/ubuntu/+source/nltk) –  3.4.5-2ubuntu0.1~esm4   Ubuntu Pro | | | | 18.04 LTS bionic | [python-nltk](https://launchpad.net/ubuntu/+source/nltk) –  3.2.5-1ubuntu0.1+esm4   Ubuntu Pro | | | | [python3-nltk](https://launchpad.net/ubuntu/+source/nltk) –  3.2.5-1ubuntu0.1+esm4   Ubuntu Pro | | | | 16.04 LTS xenial | [python-nltk](https://launchpad.net/ubuntu/+source/nltk) –  3.1-1ubuntu0.1+esm4 | | | | [python3-nltk](https://launchpad.net/ubuntu/+source/nltk) –  3.1-1ubuntu0.1+esm4 | | | | 14.04 LTS trusty | [python-nltk](https://launchpad.net/ubuntu/+source/nltk) –  2.0~b9-0ubuntu4.1~esm6   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-2026-33236](https://ubuntu.com/security/CVE-2026-33236) * [CVE-2026-33231](https://ubuntu.com/security/CVE-2026-33231) * [CVE-2026-33230](https://ubuntu.com/security/CVE-2026-33230) * [CVE-2026-0848](https://ubuntu.com/security/CVE-2026-0848) * [CVE-2026-0847](https://ubuntu.com/security/CVE-2026-0847) * [CVE-2026-0846](https://ubuntu.com/security/CVE-2026-0846)