High 7.5Published Mar 20, 2026

CVE-2026-33231NLTK has unauthenticated remote shutdown in nltk.app.wordnet_app

Updated under an hour ago (Oct 26, 2026, 3:30 PM ET)

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Exploited in the last 30 days

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.

CVSS: 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-306
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Modified
Record last updated: Sep 9, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

nltk nltk nltk:nltk (from the name)	through 3.9.3	CNA record
Red Hat Red Hat OpenShift AI 2.25 redhat:openshift_ai	from 1780069222 not affected	CISA ADP
Red Hat Lightspeed Core redhat:lightspeed_core	All versions	CISA ADP
Red Hat OpenShift Lightspeed redhat:openshift_lightspeed	Versions not stated	CISA ADP
Red Hat Red Hat Ansible Automation Platform 2 redhat:ansible_automation_platform	2	CISA ADP
nltk nltk nltk:nltk	through 3.9.3	NVD

References

References

https://github.com/nltk/nltk/security/advisories/GHSA-jm6w-m3j8-898g	x-refsource-confirm, exploit, vendor-advisory
https://github.com/nltk/nltk/commit/bbaae83db86a0f49e00f5b0db44a7254c268de9b	x-refsource-misc, patch
https://access.redhat.com/errata/RHSA-2026:19712
https://access.redhat.com/errata/RHSA-2026:24977
https://access.redhat.com/errata/RHSA-2026:37275
https://access.redhat.com/errata/RHSA-2026:65126
https://access.redhat.com/security/cve/CVE-2026-33231
https://bugzilla.redhat.com/show_bug.cgi?id=2449836
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33231.json

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.