PYSEC-2026-2237

Vulnerability from pysec - Published: 2026-03-20 23:16 - Updated: 2026-07-13 05:50
VLAI
Details

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, the NLTK downloader does not validate the subdir and id attributes when processing remote XML index files. Attackers can control a remote XML index server to provide malicious values containing path traversal sequences (such as ../), which can lead to arbitrary directory creation, arbitrary file creation, and arbitrary file overwrite. Commit 89fe2ec2c6bae6e2e7a46dad65cc34231976ed8a patches the issue.

Severity
8.1 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
Impacted products
Name purl
nltk pkg:pypi/nltk
Aliases
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {},
      "package": {
        "ecosystem": "PyPI",
        "name": "nltk",
        "purl": "pkg:pypi/nltk"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.9.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.8",
        "0.9",
        "0.9.3",
        "0.9.4",
        "0.9.5",
        "0.9.6",
        "0.9.7",
        "0.9.8",
        "0.9.9",
        "2.0.1",
        "2.0.1rc1",
        "2.0.1rc2-git",
        "2.0.1rc3",
        "2.0.1rc4",
        "2.0.2",
        "2.0.3",
        "2.0.4",
        "2.0.5",
        "2.0b4",
        "2.0b5",
        "2.0b6",
        "2.0b7",
        "2.0b8",
        "2.0b9",
        "3.0.0",
        "3.0.0b1",
        "3.0.0b2",
        "3.0.1",
        "3.0.2",
        "3.0.3",
        "3.0.4",
        "3.0.5",
        "3.1",
        "3.2",
        "3.2.1",
        "3.2.2",
        "3.2.3",
        "3.2.4",
        "3.2.5",
        "3.3",
        "3.4",
        "3.4.1",
        "3.4.2",
        "3.4.3",
        "3.4.4",
        "3.4.5",
        "3.5",
        "3.5b1",
        "3.6",
        "3.6.1",
        "3.6.2",
        "3.6.3",
        "3.6.4",
        "3.6.5",
        "3.6.6",
        "3.6.7",
        "3.7",
        "3.8",
        "3.8.1",
        "3.9",
        "3.9.1",
        "3.9.2",
        "3.9.3",
        "3.9b1"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-33236",
    "GHSA-469j-vmhf-r6v7"
  ],
  "details": "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, the NLTK downloader does not validate the `subdir` and `id` attributes when processing remote XML index files. Attackers can control a remote XML index server to provide malicious values containing path traversal sequences (such as `../`), which can lead to arbitrary directory creation, arbitrary file creation, and arbitrary file overwrite. Commit 89fe2ec2c6bae6e2e7a46dad65cc34231976ed8a patches the issue.",
  "id": "PYSEC-2026-2237",
  "modified": "2026-07-13T05:50:16.781467Z",
  "published": "2026-03-20T23:16:47.007Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-33236"
    },
    {
      "type": "WEB",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33236.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/errata/RHSA-2026:10184"
    },
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/errata/RHSA-2026:19712"
    },
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/errata/RHSA-2026:37275"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2449824"
    },
    {
      "type": "FIX",
      "url": "https://github.com/nltk/nltk/commit/89fe2ec2c6bae6e2e7a46dad65cc34231976ed8a"
    },
    {
      "type": "EVIDENCE",
      "url": "https://github.com/nltk/nltk/security/advisories/GHSA-469j-vmhf-r6v7"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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