{"id":"CVE-2026-33236","title":"NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing","summary":"NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. In versions 3.9.3 and prior, the NLTK downloader does not validate the…","severity":"high","cvss":8.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H","cwe":["CWE-22"],"vendor":"nltk","product":"nltk","affected":["nltk <= 3.9.3"],"published":"2026-03-20","updated":"2026-07-10","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-33236","references":[{"url":"https://github.com/nltk/nltk/commit/89fe2ec2c6bae6e2e7a46dad65cc34231976ed8a","label":"security-advisories@github.com"},{"url":"https://github.com/nltk/nltk/security/advisories/GHSA-469j-vmhf-r6v7","label":"security-advisories@github.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:10184","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:19712","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:37275","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/security/cve/CVE-2026-33236","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2449824","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33236.json","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33236"},{"url":"https://github.com/nltk/nltk"}],"tags":["nvd","osv","pip"],"epss":0.00575,"epssPercentile":0.45931,"ingestedAt":"2026-07-10T13:03:45.502Z","aliases":["GHSA-469j-vmhf-r6v7","PYSEC-2026-2237"],"ecosystem":"pip","slug":"CVE-2026-33236","body":"## Overview\n\nNLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. In versions 3.9.3 and prior, the NLTK downloader does not validate the `subdir` and `id` attributes when processing remote XML index files. Attackers can control a remote XML index server to provide malicious values containing path traversal sequences (such as `../`), which can lead to arbitrary directory creation, arbitrary file creation, and arbitrary file overwrite. Commit 89fe2ec2c6bae6e2e7a46dad65cc34231976ed8a patches the issue.\n\n## Affected\n\n- `nltk <= 3.9.3`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-33236)\n\nAffected packages:\n\n- `nltk <= 3.9.2`\n\nSource: https://osv.dev/vulnerability/GHSA-469j-vmhf-r6v7","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":44.6,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}