# CVE-2026-0846: nltk: A vulnerability in the `filestring()` function of the `nltk.util` module in nltk version 3.9.2 allows arbitrary file...

CVE-2026-0846 is fixed in 3 products on 1 platform, first by DEBIAN-CVE-2026-0846, released March 9, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-0846
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0059
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 9, 2026

## Description

A vulnerability in the `filestring()` function of the `nltk.util` module in nltk version 3.9.2 allows arbitrary file read due to improper validation of input paths. The function directly opens files specified by user input without sanitization, enabling attackers to access sensitive system files by providing absolute paths or traversal paths. This vulnerability can be exploited locally or remotely, particularly in scenarios where the function is used in web APIs or other interfaces that accept user-supplied input.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | nltk Debian 14 | 3.9.3-1 | [DEBIAN-CVE-2026-0846](https://patchblox.com/security/data/fix/linux/debian-cve-2026-0846.md) | Mar 9, 2026 |
| Linux | python-nltk Ubuntu 18.04.6 LTS (bionic) | 3.2.5-1ubuntu0.1+esm4 | [python-nltk 3.2.5-1ubuntu0.1+esm4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python-nltk-3.2.5-1ubuntu0.1-esm4.md) | Mar 20, 2026 |
| Linux | python3-nltk Ubuntu 18.04.6 LTS (bionic) | 3.2.5-1ubuntu0.1+esm4 | [python3-nltk 3.2.5-1ubuntu0.1+esm4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python3-nltk-3.2.5-1ubuntu0.1-esm4.md) | Mar 20, 2026 |
| Linux | python3-nltk Ubuntu 20.04 LTS (focal) | 3.4.5-2ubuntu0.1~esm4 | [python3-nltk 3.4.5-2ubuntu0.1~esm4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-python3-nltk-3.4.5-2ubuntu0.1-esm4.md) | Mar 20, 2026 |
| Linux | python3-nltk Ubuntu 22.04.1 LTS (jammy) | 3.7-1ubuntu0.1~esm2 | [python3-nltk 3.7-1ubuntu0.1~esm2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-python3-nltk-3.7-1ubuntu0.1-esm2.md) | Mar 20, 2026 |
| Linux | python3-nltk Ubuntu 24.04.5 LTS (noble) | 3.8.1-1ubuntu0.1~esm2 | [python3-nltk 3.8.1-1ubuntu0.1~esm2](https://patchblox.com/security/data/fix/linux/ubuntu-noble-python3-nltk-3.8.1-1ubuntu0.1-esm2.md) | Mar 20, 2026 |
| Linux | python3-nltk Ubuntu 26.04.1 LTS (resolute) | 3.9.2-1ubuntu0.1~esm2 | [python3-nltk 3.9.2-1ubuntu0.1~esm2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-python3-nltk-3.9.2-1ubuntu0.1-esm2.md) | Mar 20, 2026 |

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Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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