---
id: CVE-2026-0846
title: Arbitrary File Read via Absolute Path Input in nltk.util.filestring()
summary: >-
  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
  saniti…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L'
cvssSource: cna
cwe:
  - CWE-36
vendor: nltk
product: nltk/nltk
affected:
  - nltk/nltk >= unspecified <= latest
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-03-12T14:48:03.077006Z'
exploitAvailable: true
published: '2026-03-09'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T12:04:21.353Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-0846'
references:
  - url: 'https://huntr.com/bounties/007b84f8-418e-4300-99d0-bf504c2f97eb'
tags:
  - cve.org
  - exploit-available
epss: 0.00428
epssPercentile: 0.36642
ingestedAt: '2026-09-16T12:55:21.868Z'
---

## Overview

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.

## Affected

- `nltk/nltk >= unspecified <= latest`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.