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.

• CWE-79

• https://github.com/nltk/nltk/commit/1c3f799607eeb088cab2491dcf806ae83c29ad8fPatch
• https://github.com/nltk/nltk/commit/40d0bc1d484a3458d6a63ecb5ba4957ab16ba14ePatch
• https://github.com/nltk/nltk/security/advisories/GHSA-gfwx-w7gr-fvh7Exploit, Vendor Advisory

Published

Mar 20, 2026

Last Modified

Jun 17, 2026

Status

Analyzed

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-33223NATS-Server is a High-Performance server for NATS.io, a clou…5.4
• CVE-2026-33226Budibase is a low code platform for creating internal tools,…8.7
• CVE-2026-33227Improper validation and restriction of a classpath path name…4.3
• CVE-2026-33228flatted is a circular JSON parser. Prior to version 3.4.2, t…9.8
• CVE-2026-33229XWiki Platform is a generic wiki platform offering runtime s…9.8
• CVE-2026-3323An unsecured configuration interface on affected devices all…7.5
• CVE-2026-33231NLTK (Natural Language Toolkit) is a suite of open source Py…7.5
• CVE-2026-33232AutoGPT is a workflow automation platform for creating, depl…7.5
• CVE-2026-33233AutoGPT is a workflow automation platform for creating, depl…7.6
• CVE-2026-33234AutoGPT is a workflow automation platform for creating, depl…5
• CVE-2026-33235AutoGPT is a workflow automation platform for creating, depl…7.7
• CVE-2026-33236NLTK (Natural Language Toolkit) is a suite of open source Py…8.1