CVE-2026-33230 Details
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, `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.
A reflected cross-site scripting vulnerability has been identified in the NLTK (Natural Language Toolkit) WordNet Browser application, specifically in versions 3.9.3 and prior. The issue arises in the 'lookup_' route of 'nltk.app.wordnet_app', where attacker-controlled 'word' data is reflected into the response page without proper HTML escaping. This vulnerability affects users running the local WordNet Browser server, potentially leading to the execution of arbitrary JavaScript in the browser context of the application.
Users can update to NLTK version 3.9.4 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Mar 24, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-79 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| nltk nltk | <= 3.9.3 |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Mar 23, 2026 | Initial Analysis | [email protected] |
| Mar 20, 2026 | New CVE Received | [email protected] |