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, 1:19 p.m.
Last Modified :
June 17, 2026, 4:30 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.0 | HIGH | MITRE-CVE | ||||
| CVSS 3.0 | HIGH | [email protected] |
Solution
- 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.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-12199.
| URL | Resource |
|---|---|
| https://huntr.com/bounties/cee4ca6a-d17f-4746-abad-c68119633d37 | |
| https://huntr.com/bounties/cee4ca6a-d17f-4746-abad-c68119633d37 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-12199 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-12199
weaknesses.
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.
The following table lists the changes that have been made to the
CVE-2026-12199 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added Reference https://huntr.com/bounties/cee4ca6a-d17f-4746-abad-c68119633d37 Added SSVC {'id': 'CVE-2026-12199', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-17T14:20:50.833183Z'} -
New CVE Received by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'nltk', 'product': 'nltk/nltk', 'versions': [{'status': 'affected', 'version': 'unspecified', 'versionType': 'custom', 'lessThanOrEqual': 'latest'}]}] 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. Added CVSS V3 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-306 Added Reference https://huntr.com/bounties/cee4ca6a-d17f-4746-abad-c68119633d37