Vulnerability · Published Jun 17, 2026 · Assigned by @huntr_ai
CVE-2026-12199Unauthenticated Denial of Service in nltk.app.wordnet_app
High 7.5
In plain English
A high-severity missing authentication in nltk/nltk from nltk. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities).
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | nltk | no fix listed | DEBIAN-CVE-2026-12199 |
| Debian:13 | nltk | no fix listed | DEBIAN-CVE-2026-12199 |
| Debian:14 | nltk | no fix listed | DEBIAN-CVE-2026-12199 |
| Ubuntu:25.10 | nltk | no fix listed | UBUNTU-CVE-2026-12199 |
| Ubuntu:26.10 | nltk | no fix listed | UBUNTU-CVE-2026-12199 |
Affected products (as reported)
Weakness: CWE-306 · Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H