CVE-2026-12199

Unauthenticated Denial of Service in nltk.app.wordnet_app

Published Jun 17, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
Description
A vulnerability in `nltk.app.wordnet_app` up to version 3.9.3 allows unauthenticated remote shutdown of the local WordNet Browser HTTP server when started in its default mode. The server listens on all interfaces and processes a specific unauthenticated GET request (`/SHUTDOWN%20THE%20SERVER`) to terminate the process immediately via `os._exit(0)`. This results in a denial of service, impacting service availability. The issue arises due to insufficient authentication and protection mechanisms for critical server functions.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Nltk
Nltk nltk/nltk
Vendors & Products Nltk
Nltk nltk/nltk
Type Values Removed Values Added
Description A vulnerability in `nltk.app.wordnet_app` up to version 3.9.3 allows unauthenticated remote shutdown of the local WordNet Browser HTTP server when started in its default mode. The server listens on all interfaces and processes a specific unauthenticated GET request (`/SHUTDOWN%20THE%20SERVER`) to terminate the process immediately via `os._exit(0)`. This results in a denial of service, impacting service availability. The issue arises due to insufficient authentication and protection mechanisms for critical server functions.
Title Unauthenticated Denial of Service in nltk.app.wordnet_app
Weaknesses CWE-306
References
Metrics cvssV3_0

{'score': 7.5, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
@huntr_ai
Published
Updated
Jun 17, 2026, 2:21 PM
Reserved
Jun 14, 2026, 9:15 AM
Status
Deferred
Published
Jun 17, 2026, 1:19 PM
Modified
Jun 17, 2026, 4:30 PM
Severity
Moderate
Public date
Jun 17, 2026, 7:13 AM