{"cve":"CVE-2026-33230","nvd":{"published":"2026-03-20T23:16:46.680","modified":"2026-06-17T10:37:09.773","status":"Analyzed","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1},"cwes":["CWE-79"],"references":["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"],"products":["nltk:nltk"],"source":"nvd","synced_at":"2026-10-19T22:26:19.218427112+00:00"},"epss":{"cve":"CVE-2026-33230","score":0.00336,"percentile":0.2707,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-gfwx-w7gr-fvh7","url":"https://osv.dev/vulnerability/GHSA-gfwx-w7gr-fvh7","summary":"Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in nltk","modified":"2026-09-10T03:50:39.207692385Z","packages":[{"ecosystem":"PyPI","name":"nltk","purl":"pkg:pypi/nltk","ranges":["<3.9.4"],"fixed":["3.9.4"]}]},{"id":"PYSEC-2026-2235","url":"https://osv.dev/vulnerability/PYSEC-2026-2235","summary":"","modified":"2026-07-13T07:15:50.517124718Z","packages":[{"ecosystem":"PyPI","name":"nltk","purl":"pkg:pypi/nltk","ranges":["<3.9.4"],"fixed":["3.9.4"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}