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 `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.
History

Fri, 20 Mar 2026 23:00:00 +0000

Type Values Removed Values Added
Description 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 `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.
Title NLTK has a Downloader Path Traversal Vulnerability (AFO) - Arbitrary File Overwrite
Weaknesses CWE-22
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-03-20T22:47:10.308Z

Reserved: 2026-03-18T02:42:27.508Z

Link: CVE-2026-33236

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-03-20T23:16:47.007

Modified: 2026-03-20T23:16:47.007

Link: CVE-2026-33236

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.