CVE catalog

CVE-2026-33231

NLTK (Natural Language Toolkit) is a suite of open…

[CVE catalog]

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.

Severity
High · CVSS 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
Source
[NVD] · [CVE record]
EPSS
1.24% · Oct 27, 2026

Projects and upstream resources

Reported versions and fixes

Each observation applies to its named package, distribution, and release. Distribution backports can fix a vulnerability while retaining an older upstream version number.

Version impact has not been established. The original provider fields are retained below.

Provider details and historical evidence
Original provider fields
{
  "package_releases": [
    {
      "name": "nltk",
      "status": "fixed",
      "release": "sid",
      "version": "3.10.3-1"
    },
    {
      "name": "nltk",
      "status": "fixed",
      "release": "forky",
      "version": "3.10.3-1"
    },
    {
      "name": "nltk",
      "status": "vulnerable",
      "release": "trixie",
      "version": "3.9.1-2"
    },
    {
      "name": "nltk",
      "status": "vulnerable",
      "release": "bookworm",
      "version": "3.8-1"
    }
  ],
  "fixed_versions": [
    {
      "bug": 1131459,
      "name": "nltk",
      "type": "source",
      "origin": null,
      "release": "sid",
      "urgency": "not yet assigned",
      "fixed_version": "3.10.0-1"
    },
    {
      "bug": 1131459,
      "name": "nltk",
      "type": "source",
      "origin": null,
      "release": "forky",
      "urgency": "not yet assigned",
      "fixed_version": "3.10.0-1"
    },
    {
      "bug": 1131459,
      "name": "nltk",
      "type": "source",
      "origin": null,
      "release": "trixie",
      "urgency": "not yet assigned",
      "fixed_version": ""
    },
    {
      "bug": 1131459,
      "name": "nltk",
      "type": "source",
      "origin": null,
      "release": "bookworm",
      "urgency": "not yet assigned",
      "fixed_version": ""
    }
  ],
  "distribution_packages": [
    {
      "name": "nltk",
      "ecosystem": "pip",
      "fixed_version": ""
    },
    {
      "name": "nltk",
      "ecosystem": "cpe",
      "fixed_version": "not yet fixed"
    },
    {
      "name": "nltk",
      "ecosystem": "cpe",
      "fixed_version": "3.8.1-1ubuntu0.1~esm2"
    },
    {
      "name": "python3-nltk",
      "ecosystem": "cpe",
      "fixed_version": "3.8.1-1ubuntu0.1~esm2"
    },
    {
      "name": "nltk",
      "ranges": [
        {
          "fixed": "",
          "introduced": "",
          "last_affected": "3.9.3",
          "start_excluding": ""
        }
      ],
      "ecosystem": "cpe",
      "fixed_version": "",
      "provider_record_id": "NVD-CVE-2026-33231"
    }
  ]
}

[Debian bug #1131459]

Publisher notes

[trixie] nltk: Minor issue [bookworm] nltk: Minor issue

OpenFactory catalog packages

Matching against OpenFactory catalog package versions is in progress.

[Debian 12 (Bookworm)]

  • [python3-nltk]Unknown

    Source package: [nltk]

    Details (2)

    • 3.8-1 · all · bookworm

      Affected

      nvd · nltk · debian · bookworm; nvd · nltk · debian · 12

    • 3.8-1 · all · bookworm

      Affected

      nvd · nltk · debian · bookworm; nvd · nltk · debian · 12

[Debian 13 (Trixie)]

  • [python3-nltk]Unknown

    Source package: [nltk]

    Details (2)

    • 3.9.1-2 · all · trixie

      Affected

      nvd · nltk · debian · 13

    • 3.9.1-2 · all · trixie

      Affected

      nvd · nltk · debian · 13

Observed:

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [GitHub Advisory Database] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [Ubuntu Security Notices (USN)]