CVE-2026-33230
March 20, 2026
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, "nltk.app.wordnet_app" contains a reflected cross-site scripting issue in the "lookup_..." route. A crafted "lookup_<payload>" URL can inject arbitrary HTML/JavaScript into the response page because attacker-controlled "word" data is reflected into HTML without escaping. This impacts users running the local WordNet Browser server and can lead to script execution in the browser origin of that application. Commit 1c3f799607eeb088cab2491dcf806ae83c29ad8f fixes the issue.
Affected Packages
nltk (PYTHON):
Affected version(s) >=0.8 <3.9.4Fix Suggestion:
Update to version 3.9.4Related Resources (5)
Do you need more information?
Contact UsCVSS v4
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
LOW
Subsequent System Integrity
LOW
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
EPSS
Base Score:
0.03
