7.5
HIGH CVSS 3.0
CVE-2026-12199
Unauthenticated Denial of Service in nltk.app.wordnet_app
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.

INFO

Published Date :

June 17, 2026, 7:13 a.m.

Last Modified :

June 17, 2026, 7:13 a.m.

Remotely Exploit :

Yes !

Source :

@huntr_ai
Affected Products

The following products are affected by CVE-2026-12199 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Nltk nltk
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.0 HIGH MITRE-CVE
CVSS 3.0 HIGH [email protected]
Solution
Update nltk to a version that addresses the WordNet Browser HTTP server shutdown vulnerability.
  • Update nltk to version 3.9.4 or later.
  • Ensure WordNet Browser is not started in default mode.
  • Implement authentication for server management functions.
  • Restrict server network access to trusted interfaces.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-12199 vulnerability anywhere in the article.

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.