CVE-2026-33231

NLTK has unauthenticated remote shutdown in nltk.app.wordnet_app

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` allows unauthenticated remote shutdown of the local WordNet Browser HTTP server when it is started in its default mode. A simple `GET /SHUTDOWN%20THE%20SERVER` request causes the process to terminate immediately via `os._exit(0)`, resulting in a denial of service. Commit bbaae83db86a0f49e00f5b0db44a7254c268de9b patches the issue.

Affected

nltk

CVSS v3.1 CNA

7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

1.52% chance of exploitation in the next 30 days, 74th percentile

Published

2026-03-20

Updated

2026-09-09

Proof-of-concept exploits (1)

• advisories/GHSA-jm6w-m3j8-898g

Security advisories

• nltk/nltk/security/advisories/GHSA-jm6w-m3j8-898g
• nltk/nltk/commit/bbaae83db86a0f49e00f5b0db44a7254c268de9b

References

• CVE Record
• NVD entry