CVE-2026-33230

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.

The following products are affected by CVE-2026-33230 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-33230.

URL	Resource
https://github.com/nltk/nltk/commit/1c3f799607eeb088cab2491dcf806ae83c29ad8f
https://github.com/nltk/nltk/commit/40d0bc1d484a3458d6a63ecb5ba4957ab16ba14e
https://github.com/nltk/nltk/security/advisories/GHSA-gfwx-w7gr-fvh7
https://nvd.nist.gov/vuln/detail/CVE-2026-33230
https://www.cve.org/CVERecord?id=CVE-2026-33230