---
id: CVE-2026-0847
title: >-
  nltk: NLTK: Arbitrary file read via path traversal vulnerability
  (CVE-2026-0847)
summary: >-
  A flaw was found in NLTK (Natural Language Toolkit). This vulnerability allows
  a remote attacker to read arbitrary files on the server due to improper
  sanitization of file paths in several CorpusReader classes, including
  WordListCorpusRead…
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'
cvssSource: vendor
cwe: CWE-22
vendor: Red Hat
product: OpenShift Lightspeed
affected:
  - lightspeed_core
  - openshift_lightspeed
  - ansible_automation_platform 2
  - openshift_ai_rhoai
  - openshift_ai 2.25
  - openshift_ai 3.3
patched:
  - openshift_ai 2.25
  - openshift_ai 3.3
published: '2026-03-04'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T10:42:50+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0847.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0847.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-0847'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2444608'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-0847'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-0847'
  - url: 'https://huntr.com/bounties/fc69914f-36a9-4c18-8503-10013b39f966'
  - url: 'https://access.redhat.com/errata/RHSA-2026:10184'
  - url: 'https://access.redhat.com/errata/RHSA-2026:19712'
tags:
  - csaf
  - vex
  - red-hat
  - exploit-available
  - cve.org
epss: 0.00935
epssPercentile: 0.60603
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/HyperPS/CVE-2026-0847'
  checkedAt: '2026-10-27T16:52:00.256Z'
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-03-04T18:49:39.659563Z'
scores:
  vendor: 7.5
  cna: 8.6
ingestedAt: '2026-09-16T12:55:21.868Z'
---

## Overview

A flaw was found in NLTK (Natural Language Toolkit). This vulnerability allows a remote attacker to read arbitrary files on the server due to improper sanitization of file paths in several CorpusReader classes, including WordListCorpusReader, TaggedCorpusReader, and BracketParseCorpusReader. By exploiting this path traversal vulnerability, an attacker can gain unauthorized access to sensitive information, such as system files, SSH private keys, and API tokens. In certain scenarios, this could potentially lead to remote code execution.

## Vendor advisories

- **RHSA-2026:10184** · Red Hat · fixed in: Red Hat OpenShift AI 2.25 · released 2026-04-23 · [advisory](https://access.redhat.com/errata/RHSA-2026:10184)
- **RHSA-2026:19712** · Red Hat · fixed in: Red Hat OpenShift AI 3.3 · released 2026-05-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:19712)
- **Red Hat VEX** · Important · affected: Lightspeed Core, OpenShift Lightspeed, Red Hat Ansible Automation Platform 2, Red Hat OpenShift AI (RHOAI) · no fix planned: OpenShift Lightspeed, Red Hat Ansible Automation Platform 2, Red Hat OpenShift AI (RHOAI), Lightspeed Core · updated 2026-10-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0847.json)

**nltk: NLTK: Arbitrary file read via path traversal vulnerability** — rated Important by Red Hat. Released 2026-03-04, updated 2026-10-15.

Affected:

- Lightspeed Core
- OpenShift Lightspeed
- Red Hat Ansible Automation Platform 2
- Red Hat OpenShift AI (RHOAI)

Fixed:

- Red Hat OpenShift AI 2.25
- Red Hat OpenShift AI 3.3

No fix planned:

- OpenShift Lightspeed
- Red Hat Ansible Automation Platform 2
- Red Hat OpenShift AI (RHOAI)
- Lightspeed Core

Not affected:

- Red Hat OpenShift AI 2.25
- Red Hat OpenShift AI 3.3
- OpenShift Lightspeed
- Red Hat Ansible Automation Platform 2

## Remediation

For Red Hat OpenShift AI 2.25.5 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update:

https://docs.redhat.com/en/documentation/red_hat_openshift_ai/ https://access.redhat.com/errata/RHSA-2026:10184
For Red Hat OpenShift AI 3.3.3 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update:

https://docs.redhat.com/en/documentation/red_hat_openshift_ai/ https://access.redhat.com/errata/RHSA-2026:19712