7.5

CVE-2026-33231: nltk

CVSS: 7.5v3.1HighModified
AliasesGHSA-jm6w-m3j8-898gPYSEC-2026-2236UBUNTU-CVE-2026-33231
Published 20-03-2026Last modified 09-09-2026
Open JSON

Vulnerability summary

CVE-2026-33231 is a high (CVSS 7.5) vulnerability in nltk. EPSS estimates a 1.52% chance of exploitation in the next 30 days, higher than 74.1% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
40/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
1.52%
0%100%
Low · +0.30 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github

Advisory lineage

Upstream 0 · Downstream 0 · Related 2
CGA-37MM-MC53-GXH5USN-8302-1

Timeline

  1. 20-03-2026
    PublishedVulnerability first disclosed.
  2. 09-09-2026
    Last modifiedVulnerability information updated.

Description

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 metrics

7 scores · 7 sources · 1 version

EPSS trend

Probability

1.52%

Chance of exploitation in the next 30 days

Percentile

74%

Versus all other CVEs

30-day change

+0.30 pp

From 1.21% on 19-09-2026

19-09-202619-10-2026
EPSS score
1.52%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • githubUnverified

    Nltk

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Chainguard11 products
  • apache-beam-python-3.11-sdk< 2.71.0-r8
  • apache-beam-python-3.12-sdk< 2.71.0-r2
  • apache-beam-python-3.13-sdk< 2.71.0-r2
  • kubeflow-pipelines-visualization-server< 2.16.0-r3
  • label-studio< 1.23.0-r1
Wolfi6 products
  • kubeflow-pipelines-visualization-server< 2.16.0-r3
  • open-webui< 0.8.12-r2 | < 0.8.12-r1
  • py3-nltk< 3.9.4-r0
  • py3.11-nltk< 3.9.4-r0
  • py3.12-nltk< 3.9.4-r0
Debian1 product
  • nltkAll versions (No fix recorded) | < 3.10.0-1
Nltk1 product
PyPI1 product
  • nltk< 3.9.4
Ubuntu1 product
  • nltk< 2.0~b9-0ubuntu4.1~esm6 | < 3.1-1ubuntu0.1+esm4 | < 3.2.5-1ubuntu0.1+esm4 | < 3.4.5-2ubuntu0.1~esm4 | < 3.7-1ubuntu0.1~esm2 | < 3.8.1-1ubuntu0.1~esm2 | All versions (No fix recorded) | < 3.9.2-1ubuntu0.1~esm2

6 vendors · 21 products

References

16 links
Show all 16 references