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CVE-2026-33236

HIGH CVSS 3.1: 8.1 EPSS 0.04%
Updated Mar 23, 2026
Nltk
Parameter Value
CVSS 8.1 (HIGH)
Affected Versions before 3.9.3
Type CWE-22 (Path Traversal)
Vendor Nltk
Public PoC No

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.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
Required
User action required

Impact Assessment

Confidentiality
None
No data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service

CVSS Vector v3.1

Weakness Type (CWE)

Vulnerable Products 1

Configuration From (including) Up to (excluding)
Nltk Nltk
cpe:2.3:a:nltk:nltk:*:*:*:*:*:*:*:*
<= 3.9.3