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.
Published Mar 20, 2026 · corrected/updated Jun 17, 2026 · nltk nltk · evidence confidence medium
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, contains a reflected cross-site scripting issue in the route. A crafted URL can inject arbitrary HTML/JavaScript into the response page because attacker-controlled 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.
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2026-33230 is a medium public vulnerability record for nltk nltk. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether nltk nltk is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: nltk/nltk. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: CVSS 6.1. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-79. Sources contributing to this record: cve_org, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Mar 20, 2026 · NIST NVD
Detected
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, contains a reflected cross-site scripting issue in the route. A crafted URL can inject arbitrary HTML/JavaScript into the response page because attacker-controlled data is reflected into HTML without esca
Jun 17, 2026 · NIST NVD
Updated
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, contains a reflected cross-site scripting issue in the route. A crafted URL can inject arbitrary HTML/JavaScript into the response page because attacker-controlled data is reflected into HTML without esca
Affected
- cpe nltk/nltkversion unspecified
Sources
- CVE.orgVulnerability recordCVE-2026-33230
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-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, contains a reflected cross-site scripting issue in the `looku
nvd.nist.gov