---
id: CVE-2026-54293
title: >-
  NLTK (Natural Language Toolkit) is a suite of open source Python modules, data
  sets, and tutorials supporting research and development in Natural Language
  Processing
summary: >-
  NLTK (Natural Language Toolkit) is a suite of open source Python modules, data
  sets, and tutorials supporting research and development in Natural Language
  Processing. Prior to 3.10.0-rc1, nltk.data.load() in NLTK is vulnerable to
  path tr…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-22
vendor: nltk
product: nltk
affected:
  - nltk < 3.10.0
patched:
  - nltk 3.10.0
published: '2026-06-22'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T13:20:30.723'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-54293'
references:
  - url: 'https://github.com/nltk/nltk/pull/3575'
    label: security-advisories@github.com
  - url: 'https://github.com/nltk/nltk/security/advisories/GHSA-p4gq-832x-fm9v'
    label: security-advisories@github.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:42644'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:60520'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:65126'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/security/cve/CVE-2026-54293'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2491486'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://github.com/nltk/nltk/security/advisories/GHSA-p4gq-832x-fm9v'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-54293.json
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-54293'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-54293'
  - url: 'https://github.com/advisories/GHSA-p4gq-832x-fm9v'
  - url: 'https://github.com/nltk/nltk'
  - url: >-
      https://github.com/pypa/advisory-database/tree/main/vulns/nltk/PYSEC-2026-2078.yaml
tags:
  - nvd
  - cve.org
  - exploit-available
  - csaf
  - vex
  - red-hat
  - ghsa
  - pip
  - osv
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-06-22T21:18:34.399949Z'
epss: 0.00633
epssPercentile: 0.48974
aliases:
  - GHSA-p4gq-832x-fm9v
  - PYSEC-2026-2078
ecosystem: pip
ingestedAt: '2026-07-07T15:41:58.344Z'
---

## Overview

NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. Prior to 3.10.0-rc1, nltk.data.load() in NLTK is vulnerable to path traversal via URL-encoded path separators and traversal segments when using the nltk: URL scheme. The unsafe-path regex check is performed before url2pathname() decodes the %xx sequences (a classic decode-after-check / TOCTOU-style flaw), allowing an attacker to bypass the protection documented in NLTK's SECURITY.md and read arbitrary files from the filesystem. While literal traversal strings such as ../../../etc/passwd are correctly blocked, encoded variants such as %2fetc%2fpasswd, %2e%2e%2f..., and ..%2f..%2f slip past the regex and are subsequently decoded into a real filesystem path. This vulnerability is fixed in 3.10.0-rc1.

## Affected

- `nltk < 3.10.0`

## Remediation

Upgrade past the affected range:

- `nltk 3.10.0`

## Package advisory (CVE-2026-54293)

Affected packages:

- `nltk <= 3.9.4`

Source: https://github.com/advisories/GHSA-p4gq-832x-fm9v

## Vendor advisories

- **RHSA-2026:42644** · Red Hat · fixed in: Red Hat OpenShift AI 2.25 · released 2026-07-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:42644)
- **RHSA-2026:65126** · Red Hat · fixed in: Red Hat OpenShift AI 2.25 · released 2026-09-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:65126)
- **RHSA-2026:60520** · Red Hat · fixed in: Red Hat OpenShift AI 3.4 · released 2026-08-27 · [advisory](https://access.redhat.com/errata/RHSA-2026:60520)
- **Red Hat VEX** · Important · affected: Exploit Intelligence, Red Hat Ansible Automation Platform 2, Red Hat OpenShift AI (RHOAI) · no fix planned: Red Hat Ansible Automation Platform 2, Exploit Intelligence, Red Hat OpenShift AI (RHOAI) · updated 2026-09-08 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-54293.json)