CVE-2026-33236CWE-22

NLTK has a Downloader Path Traversal Vulnerability (AFO) - Arbitrary File Overwrite

High · published March 20, 2026

CVSS v3.1
8.1
EPSS
1%
Percentile
53.9
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.1 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00734 · 53.9th percentile
Weakness
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Published
2026-03-20T22:47Z
EPSS history
Timeline
  • 20 MAR 22:47Z
    NLTK has a Downloader Path Traversal Vulnerability (AFO) - Arbitrary File Overwrite
    cvelistv5