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CVE-2026-33236

CVE-2026-33236 · NLTK has a Downloader Path Traversal Vulnerability (AFO) - Arbitrary File Overwrite

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 8.1 · High · EPSS 0.6% · Fix available

Published
Updated

Stack: system · python

Affected products and versions

  • nltk

    Versions
    • <= 3.9.3: Affected

    No fix published

  • nltk Debian:12

    Versions
    • 3.10.0-1
    • 3.10.1-1
    • 3.10.3-1
    • 3.8-1
    • 3.8.1-1
    • 3.9.1-1
    • 3.9.1-2
    • 3.9.2-1
    • 3.9.3-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • nltk Debian:13

    Versions
    • 3.10.0-1
    • 3.10.1-1
    • 3.10.3-1
    • 3.9.1-2
    • 3.9.2-1
    • 3.9.3-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • nltk Debian:14

    Versions
    • 3.9.1-2
    • 3.9.2-1
    • 3.9.3-1
    Affected ranges
    • ECOSYSTEM: < 3.10.0-1

    Update to 3.10.0-1

  • nltk PyPI

    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
    • 3.9b1
    Affected ranges
    • ECOSYSTEM: ≤ 3.9.2

    No fix published

  • nltk PyPI

    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
    Affected ranges
    • ECOSYSTEM: < 3.9.4

    Update to 3.9.4

  • nltk Ubuntu:Pro:14.04:LTS

    Versions
    • 2.0~b9-0ubuntu4
    • 2.0~b9-0ubuntu4.1~esm2
    • 2.0~b9-0ubuntu4.1~esm4
    • 2.0~b9-0ubuntu4.1~esm5
    Affected ranges
    • ECOSYSTEM: < 2.0~b9-0ubuntu4.1~esm6

    Update to 2.0~b9-0ubuntu4.1~esm6

  • nltk Ubuntu:Pro:16.04:LTS

    Versions
    • 3.0.4-1
    • 3.0.5-1
    • 3.1-1
    • 3.1-1ubuntu0.1
    • 3.1-1ubuntu0.1+esm1
    • 3.1-1ubuntu0.1+esm2
    • 3.1-1ubuntu0.1+esm3
    Affected ranges
    • ECOSYSTEM: < 3.1-1ubuntu0.1+esm4

    Update to 3.1-1ubuntu0.1+esm4

  • nltk Ubuntu:Pro:18.04:LTS

    Versions
    • 3.2.4-1
    • 3.2.5-1
    • 3.2.5-1ubuntu0.1
    • 3.2.5-1ubuntu0.1+esm1
    • 3.2.5-1ubuntu0.1+esm2
    • 3.2.5-1ubuntu0.1+esm3
    Affected ranges
    • ECOSYSTEM: < 3.2.5-1ubuntu0.1+esm4

    Update to 3.2.5-1ubuntu0.1+esm4

  • nltk Ubuntu:Pro:20.04:LTS

    Versions
    • 3.4.5-1
    • 3.4.5-2
    • 3.4.5-2ubuntu0.1~esm1
    • 3.4.5-2ubuntu0.1~esm2
    • 3.4.5-2ubuntu0.1~esm3
    Affected ranges
    • ECOSYSTEM: < 3.4.5-2ubuntu0.1~esm4

    Update to 3.4.5-2ubuntu0.1~esm4

  • nltk Ubuntu:Pro:22.04:LTS

    Versions
    • 3.5-1
    • 3.6.5-1
    • 3.6.7-1
    • 3.7-1
    • 3.7-1ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: < 3.7-1ubuntu0.1~esm2

    Update to 3.7-1ubuntu0.1~esm2

  • nltk Ubuntu:Pro:24.04:LTS

    Versions
    • 3.8.1-1
    • 3.8.1-1ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: < 3.8.1-1ubuntu0.1~esm2

    Update to 3.8.1-1ubuntu0.1~esm2

  • nltk Ubuntu:25.10

    Versions
    • 3.9.1-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • nltk Ubuntu:26.10

    Versions
    • 3.9.2-1
    • 3.9.3-1
    • 3.10.0-1
    • 3.10.1-1
    • 3.10.3-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • nltk Ubuntu:Pro:26.04:LTS

    Versions
    • 3.9.1-2
    • 3.9.1-2build1
    • 3.9.2-1
    • 3.9.2-1ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: < 3.9.2-1ubuntu0.1~esm2

    Update to 3.9.2-1ubuntu0.1~esm2

Original sources

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