{"id":"UBUNTU-CVE-2021-3828","details":"nltk is vulnerable to Inefficient Regular Expression Complexity","modified":"2026-01-30T02:46:50.491346Z","published":"2021-09-27T13:15:00Z","related":["USN-5215-1"],"upstream":["CVE-2021-3828"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-3828"},{"type":"REPORT","url":"https://github.com/nltk/nltk/pull/2816"},{"type":"REPORT","url":"https://huntr.dev/bounties/d19aed43-75bc-4a03-91a0-4d0bb516bc32"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5215-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-3828"}],"affected":[{"package":{"name":"nltk","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/nltk@3.1-1ubuntu0.1+esm1?arch=source&distro=esm-apps/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.1-1ubuntu0.1+esm1"}]}],"versions":["3.0.4-1","3.0.5-1","3.1-1","3.1-1ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.1-1ubuntu0.1+esm1","binary_name":"python-nltk"},{"binary_version":"3.1-1ubuntu0.1+esm1","binary_name":"python3-nltk"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3828.json"}},{"package":{"name":"nltk","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/nltk@3.2.5-1ubuntu0.1+esm1?arch=source&distro=esm-apps/bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.2.5-1ubuntu0.1+esm1"}]}],"versions":["3.2.4-1","3.2.5-1","3.2.5-1ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.2.5-1ubuntu0.1+esm1","binary_name":"python-nltk"},{"binary_version":"3.2.5-1ubuntu0.1+esm1","binary_name":"python3-nltk"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3828.json"}},{"package":{"name":"nltk","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/nltk@3.4.5-2ubuntu0.1~esm1?arch=source&distro=esm-apps/focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.4.5-2ubuntu0.1~esm1"}]}],"versions":["3.4.5-1","3.4.5-2"],"ecosystem_specific":{"binaries":[{"binary_version":"3.4.5-2ubuntu0.1~esm1","binary_name":"python3-nltk"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3828.json"}},{"package":{"name":"nltk","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/nltk@3.6.5-1?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.6.5-1"}]}],"versions":["3.5-1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.6.5-1","binary_name":"python3-nltk"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3828.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}