NLTK 3.9.2 Path Traversal in Corpus Readers allows Arbitrary File Read
CVE-2026-0847 Published on March 4, 2026

Path Traversal in nltk/nltk
A vulnerability in NLTK versions up to and including 3.9.2 allows arbitrary file read via path traversal in multiple CorpusReader classes, including WordListCorpusReader, TaggedCorpusReader, and BracketParseCorpusReader. These classes fail to properly sanitize or validate file paths, enabling attackers to traverse directories and access sensitive files on the server. This issue is particularly critical in scenarios where user-controlled file inputs are processed, such as in machine learning APIs, chatbots, or NLP pipelines. Exploitation of this vulnerability can lead to unauthorized access to sensitive files, including system files, SSH private keys, and API tokens, and may potentially escalate to remote code execution when combined with other vulnerabilities.

NVD

Vulnerability Analysis

CVE-2026-0847 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. An automatable proof of concept (POC) exploit exists. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
NONE
Availability Impact:
NONE

Weakness Type

What is a Directory traversal Vulnerability?

The software uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the software does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

CVE-2026-0847 has been classified to as a Directory traversal vulnerability or weakness.


Products Associated with CVE-2026-0847

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-0847 are published in these products:

Canonical Ubuntu Linux
 
Red Hat Openshift Ai
 
Red Hat Lightspeed Core
 
Red Hat Openshift Lightspeed
 
Red Hat Ansible Automation Platform
 

Affected Versions

nltk/nltk: Red Hat OpenShift AI 2.25: Red Hat OpenShift AI 3.3: Red Hat Lightspeed Core: Red Hat OpenShift Lightspeed: Red Hat Ansible Automation Platform 2: Red Hat OpenShift AI (RHOAI):

Exploit Probability

EPSS
0.75%
Percentile
50.00%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.